Because of a typographical error, a story in yesterday's Washington Post incorrectly reported the number of customers served by Washington Gas Light Co. The correct number is 530,000.

The Washington Gas Light Company announced yesterday that it has enough natural gas reserves to take on new customers again for the first time in five years.

The gas company said it could start hooking up 10,600 new residential and small business gas lines immediately if it gets approval of utility regulators in the District, Maryland and Virginia.

Increased gas shipments from pipeline suppliers, a build-up of stored gas reserves, energy conservation efforts and attrition of customer since the 1972 moratorium make the decision possible, company officials said.

New service would be offered for 3,000 customers in the District, 4,300 in the Maryland suburbs and 3,300 in the Virginia suburbs. Two Washington Gas Light susbsidiaries, Shenandoah Gas Company in Winchester, Va., and Frederick Gas Company in Frederick, Md. each will accept 300 new customers.

he new hookups would amount to about 2 per cent of Washington Gas Light's 53,000 customers, who use about 100 billion cubic feet of gas a year.

"The company's gas supply has stabilized," Washington Gas Light president Paul E. Reichardt said at a news conference. "Our pipeline suppliers predict a gradual increase in supply over the next few years."

He said the company already has enough fuel, committed and in storage, to take on new business "without jeopardizing service to our existing customers."

Another Washington Gas Light official said he could not estimate the impact of the new business on the company's profits.A 2 per cent increase in customers would be equivalent to adding $5 million a year to the 1976 annual revenues of $270 million.

Though gas rates have gone up steadily and gas company revenues have increased from $162 million to $270 million in five years, Washington Gas Light's profits have gone down in two of the last four years.

"Because the company has been unable to accept new customers since 1972 as a result of the gas shortage, there has been no growth to help us offset the continuing inroads to inflation," Reichardt noted in his latest report to stockholders.

New service will be offered to single-family homes, apartments and small commercial customers using up to 50,000 cubic feet of gas a day.

Washington Gas Light is the latest in a number of utilities to ask to lift moratoriums on new customers. More will join the trend as gas supplies improve, predicted an official of the American Gas Association.

Utility regulators in the District, Maryland and Virginia said it will take at least a month - and probably longer - to evaluate the request to add new customers. Spokesmen warned that there could be opposition from groups that fear existing gas customers would risk curtailments if new customers are added.

In Fairfax County, for example, the Board of Supervisors voted yesterday to oppose state approval of Washington Gas's application for as long as the utility requires that outdoor gas lamps in Fairfax subdivisions be phased out. Board Chairman John F. Herrity said the lamps are a "significant deterrent to crime."

Home builders and developers, however, are eager to lift the moratorium which has meant all new houses built here in the past five years have had more expensive electric or oil heat in stalled.

The gas company said it might take as long as two years to generate demand for all the 10,600 new customers. No priorities have been made set, for single family, multi-family or commercial business.

Energy conservation efforts, ranging from turned down thermostats to new energy efficient buildings, have trimmed gas demand here by an estimated 7 per cent easing the pressure on supply, a gas company spokesman noted.

In addition, since the moratorium began more than 7,000 meters have been taken out of service due to Metro construction, urban renewal and other demolition.

The attrition alone is equivalent to 4,300 gas-heated homes, or nearly half the new customers the gas company wants to add.

The utility said it has been promised increased gas shipments from its two pipeline sources, Columbia Gas Transmission Corp., which supplies 85 per cent of gas used here, and Transcontinental Gas Pipeline Corp., supplier of the other 15 per cent.

A new gas supply plan by Columbia Gas in effect guarantees that Washington Gas Light will get 3 per cent more gas this winter than it got last winter. By spring, Columbia Gas expects to be importing liquefied natural gas (LNG) from Algeria, adding another 6 to 8 per cent to Washington Gas Light's supply.

Already on hand for the winter are 2.3 billion cubic feet of gas in a storage field in Hampshire, W. Va., and 1.4 billion cubic feet more in a Louisiana storage field. This is about 800 million cubic feet more than was available last year.

Washington Gas Light officials stressed that opening the doors to new business is an experimental move. "We've been out of the market for five years, so we don't know what is going to happen," said a spokesman. "After we see what the demand is, we can see what we can do beyond this."

After years of steadily expanding sales in which natural gas become the cheapest and dominant fuel for home heating in this area, gas supplies began shrinking in the early 1970s.

Transco cut its shipments to Washington Gas Light in 1971 and Columbia Gas began curtailments the following year. At that time, utility regulators set the moratorium on new customers as a means of assuring supplies for existing customers.

The gas situation was at its worst last winter when the coldest weather in decades forced the closing of schools and some business in Virginia. At the same time, however, there were adequate gas supplies in Maryland and the District. Such inequities will be avoided by a new three-way natural gas allocation pact this year that balances supplies across government boundaries, the gas company said.

Reichardt said gas supplies will bottom out this year, than turn upward in the spring. Gas prices, however, will continue rising, a Gas Light spokesman said.

Washington Gas Light asked in July for a 10.3 per cent rate increase in the District that would add $8.6 million to utility bills. A 2.6 per cent, $3.7 million rate increase in Maryland was asked in September. Neither has been approved yet.

In Virginia a request for a 10 per cent, $8.6 million raise has been pending since last year. A 5 per cent temporary surcharge was granted last October.