Opponents of legislation to trim the District of Columbia workers' compensation program won a tactical victory yesterday when the City Council voted to block immediate consideration of the measure.

The 7-to-6 decision, taken in a chamber packed beyond its 200-person capacity by union members and a smaller number of businessmen, standing three deep along the walls, will cause a delay of two weeks.

Before the vote, Mayor Marion Barry sent a letter to the council asking for a postponement of six to eight weeks, contending the program's "complexity . . . and impact" require more study. The council did not act on his request.

The dispute over changes in the compensation program, which pays benefits to workers injured on their jobs, is bitterly contested by businesses and unions. Business spokesmen contend the cost is becoming prohibitive, while union leaders say the proposed curtailments are harmful to workers.

Both sides initiated a last-minute lobbying effort to line up support among council members for their positions.

The cost of workers' compensation insurance premiums paid by employers here has soared more than 600 percent in the last eight years. The maximum benefit has risen under a cost-of-living escalator from $70-a-week per employe to $426. Benefits in Maryland and Virginia are much lower -- in Maryland the top figure is $220 and in Virginia it is $198.

Yesterday's vote on the bill, sponsored by Willie J. Hardy (D-Ward 7), was on narrow parliamentary grounds. Several members on both sides stressed that the vote was no test of the ultimate outcome.

Wilhelmina J. Rolark (D-Ward 8), a critic of the bill, triggered the vote. She raised a point of order that Hardy, as chairman of the council's Housing and Economic Development Committee, had violated a procedural rule by failing to have her committee vote specifically to adopt the official report that describes the bill.

Hardy's committee approved the legislation Dec. 11, but the report was drafted afterward and not voted upon. Another committee meeting is scheduled for today, where such a vote could come.

That would move the measure to the council for legislative consideration Feb. 19, two weeks later than Hardy had planned. Barry's request for a delay also could be considered on that date.

Despite the brevity of the delay, union members applauded the outcome after listening quietly for the most part to the 90-minute debate.

"The bill that was up was not for theworking man and the poor man," said Samuel Lee Rice, a member of Local 891 of the Cement Masons Union, who attended wearing his hard hat and overalls.

Construction executive Roger Blunt, speaking for the Greater Washington Board of Trade, a major backer of the Hardy bill, said he was not surprised by the council vote. "I think they are somewhat intimidated by the presence of [so many from ] labor," he said.

The Washington Post reported last summer that Hardy's legislation -- which would freeze benefits and tighten administrative provisions -- was drafted in large part by the Board of Trade and that much of her original draft report on the measure was lifted verbatim from a board lobbying document. That draft was later withdrawn.

The debate on Rolark's parliamentary question found Council Chairman Arrington Dixon (D) and James M. Christian, the council's chief lawyer and a Dixon appointee, on opposite sides.

Christian voiced an opinion in Rolark's favor, saying committees must vote specifically on legislative reports. Dixon ruled, however, that this procedure was bypassed so often that a precedent had been set.

Rolark demanded and obtained a vote that rejected Dixon's position. Joining Rolark were David A. Clarke (D-Ward 1), Hilda Mason (Statehood-At Large), Jerry A. Moore Jr. (R-At Large), John L. Ray (D-At Large), Nadine P. Winter (D-Ward 6) and John A. Wilson (D-Ward 2). Supporting Dixon were Hardy, Charlene Drew Jarvis (D-Ward 4), Betty Ann Kane (D-At Large), Polly Shackleton (D-Ward 3) and William R. Spaulding (D-Ward 5).

In a related matter, Ben Dudley, communications director for the Washington Urban League, denied a statement made by union leaders at a rally Friday night and reported yesterday in The Washington Post that the league had opposed Hardy's bill. Dudley said the league has taken no position.

Before debating the compensation measure, the council voted 11 to 2 -- with Rolark and Mason opposed -- to renew emergency legislation permitting landlords of an estimated 57,000 oil-heated apartments to raise rents 3.5 to 7 percent to cover increased costs. The new legislation will be effective through the end of April.

Yesterday, the city's Rental Accommodations Commission amended the regulations that cover the way the increases are calculated. Landlords will base the increases on a comparison of oil costs during the current heating season (Oct. 1, 1979, to April 30, 1980) with the same period a year earlier.

Landlords must certify the increases with the city's rent administrator. If the resulting rental income proves to be higher than the actual increased costs, refunds must be made to tenants by June 1.