How to Analyse a City Gas Distribution Stock

In October 2024 the government quietly cut the share of cheap, price-controlled domestic gas (APM) that city gas distributors get for their CNG business. Mahanagar Gas had been running on roughly 57–58% APM for its CNG sales; through the successive cuts that share fell to around 47% and then to about 37% by Q1 FY26, and by Q2 FY26 APM covered "only about 35% of domestic requirements" (MGL Q1 FY26 and Q2 FY26 concalls; Inve data). The company did not lose a single customer or sell a litre less gas. It simply had to buy the shortfall as imported RLNG at multiples of the APM price — and its full-year FY25 EBITDA fell to roughly ₹1,510 crore, down from a record ₹1,843 crore in FY24, a drop management attributed to the reduction in APM allocation and the higher gas cost weighing on margins (MGL Q4 FY25 concall, May 2025; figures from Inve data). EBITDA per standard cubic metre, the number that actually runs this business, slid from a record ₹13.95 in Q4 FY24 to ₹8.00 by Q3 FY26 (Inve data). (Illustration of how to read the numbers, not a view on the stock.)

That single episode tells you what a city gas distribution (CGD) company really is. It is not a "gas demand growth" story, however much the brochures lean on India's 6%-to-15% gas-in-the-energy-mix ambition. It is a regulated spread on volume: the distributor earns a margin per unit of gas moved through its pipes, and the two things that decide that margin — the price it pays for gas and how much price-controlled gas it is allotted — are set by a policy desk in Delhi, not by the company. Read a CGD the way an analyst reads it and you stop watching revenue, which moves with gas prices and tells you almost nothing, and start watching volume and margin-per-scm, which tell you everything.

A note on the boundary first: you cannot model the government's next APM allocation from a transcript. What you can do is read where the margin and volume are heading, and check whether management's account of the policy risk survives the Q&A.

Why is a CGD a regulated-spread-on-volume business?

Strip a CGD down and it is a tollbooth on a pipe. The company is awarded an exclusive licence — a "geographical area," or GA — to lay the last-mile network and sell natural gas in a city or district for a fixed marketing-exclusivity period. It buys gas at the city gate and sells it as CNG to vehicles, as piped natural gas (PNG) to homes and to industry. The economic engine is the margin between landed gas cost and selling price, multiplied by the volume that flows. Revenue is a distraction: when global gas prices spike, revenue balloons while the company may actually be earning less per unit. When prices fall, revenue shrinks even as margins fatten.

That framing fixes two beginner errors. First, revenue growth means almost nothing — a CGD can post 30% revenue "growth" purely because LNG prices rose, with flat volumes and squeezed margins underneath. Second, the regulator is a silent third party on the income statement. The single biggest swing factor in a CGD's profit is not competition or execution — it is how much APM gas the government allocates to its CNG segment, because APM is priced far below imported RLNG. A CGD with a high APM share earns a comfortable margin; the same company, same pipes, same customers, earns far less the day that allocation is cut. The question is never "is gas demand growing?" but "is the volume growing, is the margin-per-scm holding, and how exposed is that margin to the next allocation decision?"

Volume (mmscmd): the number revenue hides

Volume is the toll count — how much gas physically moved, measured in million metric standard cubic metres per day (mmscmd). It is the cleanest measure of the business because it strips out the gas-price noise that distorts revenue. Where to find it: management states it on every concall and in the investor PPT, sometimes as a daily run-rate, sometimes as a quarterly average — read the unit carefully (a "1.26 MMSCMD/day" CNG line sits inside a larger total). It is rarely a clean line in the income statement, so this is a transcript-and-deck metric.

What "good" looks like is mid-to-high single-digit annual volume growth, ideally driven by the existing GAs maturing rather than only by acquiring new ones. For scale: IGL ran total volume of about 5.43 mmscmd in Q3 FY26 (IGL Q3 FY26 concall), Mahanagar Gas about 4.62 mmscmd in the same quarter (Inve data, Q3 FY26), and Gujarat Gas the largest at roughly 8.4 mmscmd in Q2 FY26 (Inve data). The discipline is to track volume and margin together: volume up while margin-per-scm collapses is not growth you should pay for.

EBITDA per scm: the one number that runs the business

If you learn one metric for this sector, learn this one. EBITDA per standard cubic metre is the company's gross spread after operating costs, expressed per unit of gas sold — the toll, net of running the toll booth. It is the truest measure of a CGD's economics because it neutralises both gas-price swings and volume scale, leaving you with how much the company actually keeps on each unit.

Where to find it: almost never in the financial statements. It lives in the investor presentation and in the concall Q&A, and it is the number analysts spend half the call interrogating. A "good" range sits roughly between ₹5 and ₹9 per scm for the listed majors, with the understanding that the top of that range usually reflects a windfall — cheap APM gas plus high alternate-fuel prices — that does not persist.

Here is the spread doing its work. Mahanagar Gas, the most APM-dependent of the majors because its book is so CNG-heavy, printed a record ₹13.95/scm in Q4 FY24 (Inve data) — and rather than let that peak set the bar, management consistently steered investors toward absolute profit growth instead of a fixed per-unit margin, declining to treat the windfall quarter as a run rate. That stance proved prescient. By Q3 FY26 the figure was ₹8.00 (Inve data), well below the peak. The investor who anchored on ₹14 paid for a windfall; the one who read management's own refusal to stand behind it did not.

Contrast the level across the three majors and the structure shows through: IGL guided to a long-term "7% to 8%" margin range — "we should be near to 7% going forward… the long-term guidance remains that 7% to 8% is our target range" (IGL Q3 FY26 concall) — while Gujarat Gas, whose volume is dominated by price-sensitive industrial customers, has at times guided to a thinner ₹4.50/scm band (GUJGASLTD Q3–Q4 FY25 concalls; Inve data). Same business, three different margin profiles, driven almost entirely by mix and APM exposure.

CNG vs PNG vs industrial: why the mix decides the risk

A CGD's volume splits into three buckets, and they behave nothing alike. CNG (transport fuel) and domestic PNG (cooking gas to homes) are the "priority" segment — historically fed with cheap APM gas, sticky, and high-margin. Industrial and commercial PNG is the swing segment — large volumes, but the customer can switch to a cheaper alternate fuel (propane, furnace oil, coal) the moment piped gas loses its price edge.

The mix is therefore a risk map. A CNG-and-domestic-heavy book is more profitable but more exposed to APM allocation cuts; an industrial-heavy book is lower-margin and exposed to fuel-switching. Mahanagar Gas is the clean example of the first: in Q3 FY26 its 4.62 mmscmd split as CNG 3.28, domestic PNG 0.60 and industrial-commercial 0.74 mmscmd (Inve data) — roughly 70% CNG, which is exactly why an APM cut hit it so hard. Gujarat Gas is the clean example of the second, and where to see the danger is its Morbi ceramics cluster: when imported gas got expensive, Morbi industrial volume "dropped from 2.87 MMSCMD to 2.51 MMSCMD" and then to 1.68 mmscmd as customers shifted to propane, with management openly conceding propane had taken share and that it now had to "become an integrated energy supplier" — i.e. sell propane itself — to win the volume back (GUJGASLTD Q1–Q2 FY26 concalls; Inve data). Where to find the mix: the investor PPT breaks it out; the concall fills in the why behind any shift.

Gas sourcing cost and the APM allocation: the policy lever

This is the metric most retail investors never look at and analysts obsess over. A CGD sources gas from a stack: cheap, price-controlled APM (domestic, allocated by the government); intermediate domestic sources (new-well gas, HPHT); and expensive imported RLNG, linked to global LNG or to Brent crude. The blend is the cost of goods, and the APM share within it is the margin.

The mechanism that broke FY25 margins across the sector: as CGD gas demand grew and domestic APM output stayed flat, the government repeatedly trimmed the APM allocated to CNG. Each trim forced distributors to backfill with RLNG at several times the price. IGL spelled the new normal out: its Q3 FY26 sourcing mix was "43% APM, 7% NWG, 6% HPHT, and 42% RLNG," and management's forward view was blunt — "it will be 50-50, 50% RLNG and 50% from domestic sources" (IGL Q3 FY26 concall). Read that as a structural margin headwind: a book that was once dominated by sub-₹500-per-mmbtu APM gas is moving toward half-imported. Where to find it: entirely in the concall and PPT — the income statement shows only the blended cost buried inside expenses, never the allocation that drives it.

The homely way to hold this: a CGD is a bakery that the government grants a daily quota of subsidised flour. The bread price is semi-fixed, so profit is the subsidised-flour share. The baker did nothing wrong the morning the quota was halved — but half the loaves now use flour bought at the open-market price, and the margin on every one of those loaves shrinks. You cannot understand the baker's earnings without knowing the quota, and the quota is set by someone who has never met the baker.

New connections and CNG stations: the growth you can verify

The forward-looking operating metrics are CNG station count, domestic PNG connections added, and industrial customers signed — the infrastructure that locks in tomorrow's volume. These are cleanly disclosed (PPT and concall) and worth tracking because they are management's guidance you can later audit. IGL guided to adding 80–100 CNG stations a year for the next three to five years, on a network already in the high-900s (~955 stations) (IGL Q3 FY26 concall; Inve data); ATGL reported 705 CNG stations and 1.1 million household customers by Q4 FY26 (Inve data); Gujarat Gas added roughly 38,600 new domestic connections in Q2 FY26 and is targeting around 1,000 CNG stations over the next two to three years (Inve data). "Good" is steady station and connection addition tracking the stated capex plan — and crucially, converting into volume. Connections that grow while volume stalls mean the network is being built ahead of demand, which is capital parked, not capital working.

How do you value a CGD?

Because a CGD's profit swings with a policy lever and a gas-price cycle, the wrong move is to capitalise a peak-margin year. Two lenses, used together.

P/E and EV/EBITDA on normalised margin, not peak. The right way to value a CGD is to ask what EBITDA per scm the business earns through a full APM cycle, multiply by a credible volume trajectory, and value that — not the windfall quarter. The reason MGL's stock can look "cheap" on trailing earnings after a peak and "expensive" after an allocation cut is that the market is repricing the normalised spread, not the reported number. An investor who put MGL on a low trailing P/E at ₹13.95/scm was buying a multiple on a margin the company itself declined to stand behind — and FY26 nine-month profit of ₹715 crore against FY25's ₹1,039 crore (Inve data) is what reverting toward normal looks like.

Margin-per-scm and APM policy as the discount-rate question. Two CGDs on the same EV/EBITDA are not equally valued if one runs a 70% CNG book on shrinking APM and the other a diversified book with secured long-term RLNG. The first carries more policy risk in its margin and deserves a wider margin of safety. This is the CGD analogue of normalising a cyclical — the same instinct you'd bring to reading a cement company through the cycle, where capitalising peak realisations is the classic trap.

A worked case: said vs did at Mahanagar Gas

Put the timeline together and the discipline becomes concrete (illustration, not a view on the stock; figures from Inve data and the cited MGL concalls):

Read the first and last rows together. The company was candid throughout — it never guided that ₹14 would last, and it told you on the record that absolute profit growth, not a fixed per-unit margin, was the goal. The number that betrayed the windfall was not revenue (which held up on volume and price) and not profit alone — it was the APM share, falling from ~58% to ~35% over a handful of quarters, dragging EBITDA/scm down with it almost mechanically. An investor who tracked the sequence of the APM allocation alongside the margin saw the de-rate coming a year before the trailing P/E "looked cheap." This is the pattern Inve's Promise Tracker is built to surface: each forward commitment — a margin band, a volume-growth target, a capex plan — pinned to the quarter and quote it was made in, with a verdict as later calls come in. (A read on how management communicated through one policy cycle, not a lifetime verdict.)

Red flags specific to CGDs

• Revenue up, volume flat, margin-per-scm down. The classic gas-price illusion — top line flatters while the business shrinks per unit. Always reconcile revenue to volume.
• A high-CNG book talking down APM risk. The more CNG-heavy the volume, the more the margin rides on an allocation the company doesn't control. Reassurance that "APM is not a concern" from a 70%-CNG distributor is the answer to distrust.
• Industrial volume bleeding to alternate fuels. When propane or furnace oil undercuts piped gas, the swing segment walks — as Morbi showed Gujarat Gas. A management that blames "temporary" softness without addressing the price gap is postponing the problem.
• GA expansion outrunning volume. Bidding aggressively for new geographical areas, then booking the capex while volumes lag, parks capital at low returns and flatters the "growth" narrative.
• Anchoring guidance to a windfall quarter. Watch whether management itself disowns a peak margin (MGL did) or quietly lets the market extrapolate it. The latter is where the de-rate is built.

Frequently asked questions

The owner's question

Where this read can be wrong. The strongest case against everything above is that the APM cut may prove to be the trough, not a trend. India keeps adding domestic gas (new-well and HPHT output), the regulator has every incentive to keep CNG competitive against petrol and diesel, and a CGD's marketing exclusivity in its GAs is a genuine, decades-long moat that no spreadsheet of one bad year captures. An investor who sold MGL on the FY25 margin collapse, reading it as structural, would have mistaken a policy-cycle dip for permanent impairment — and the same management candour that warned the peak wouldn't last also tells you the franchise underneath is intact. Reading the APM share against the margin tells you when a windfall is unwinding; it does not tell you the long-run normalised spread, and it cannot value the exclusivity that outlasts any single allocation decision.

So invert the question you bring to a CGD's results. Don't ask "is gas demand growing?" Ask: if the government halved this company's cheap-gas quota tomorrow, how much of its margin would survive — and does its mix, its sourcing contracts and its pricing power give it anywhere to stand? A 70%-CNG book leaning on a 35% APM share has thin ground; a diversified book with secured gas and real pricing power has more.

And the owner's question, the one to sit with before buying any city gas distributor: what must I believe about the next decade of APM policy, gas prices and electric-vehicle adoption — not this quarter's margin — for this licence to still be worth its capital? If the honest answer leans on a peak-margin quarter rather than the franchise underneath it, you have read the windfall, not the business.

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