Washington Gas Light Co. yesterday raised the price tag on its latest rate increase request for District of Columbia customers from $8.6 million to $11 million.

If approved by the Public Service Commission, the average customer who heats with natural gas would see the gas bill increase from $532 a year to $593.

The average bill for customers without gas heat would jump from $118 to $142.

Washington Gas Light filed a rate increase request in July 30, then raised the amount yesterday to reflect the latest reports on the company earnings.

The gas company reported a loss of $5.6 million for the quarter ended Sept. 30 and said that for the previous 12 months it earned profits of $20 million, compared to $9.5 million the previous year. But the utility said its earnings still fell short of the amount the company needs.

The amended rate increase application includes changes in the complicated gas pricing formula that are intended to equalize the rates paid by heating and non-heating customers.

Washington Gas customers pay a fixed monthly fee called a "systems charge," from September through May, plus a variable amount based on how much gas they use.

The new rate request cuts the systems charge for heating customers who use small amounts of gas from 8 to $5 a month, but leaves the $8 fee for larger customers. The systems charge for heating customers who use small amounts of gas from $8 to $5 a month, but leaves the $8 fee for larger customers. The systems charge for non-heating customers increase from $3.75 to $5.

The company said the shift was necessary because the cost of serving non-heating customers is "now being borne to a large extent by other customers." The change would reduce, but not eliminate, the subsidy given non-heating customers by those who heat with gas, the company said.

At the same time, the gas company proposed raising the price of gas used by 13.8 per cent, from 29 cents to 33 cents a therm. A therm is a unit of heat by which natural gas is measured.

Washington Gas Light said the effect of the changes would add up this way:

The average non-heating customer's bill would increase from $9.88 a month to $11.91 a month or 20 per cent.

The average small heating customer's bill would go from $24.76 to $24.97, less than 1 per cent.

The average large heating customer's bill would increase from $44.37 to $49.47 or 11.4 per cent.

Most residential heating customers fall into the last category.

The systems charge would increase from $16.50 to $25 a month for most commercial heating customers, but would decrease for some small commercial users.

Rates for metered apartments and interruptable users would also be increased, but the amount was not specified in the gas company announcement.

The changes in the rate increase request were announced late Friday. Washington Gas Light officials could not be reached for comment.

The gas company has been plagued by low profits recently, which company officials complained are below utility industry averages.