Congress gave final approval early this morning to the District's $3.9 billion appropriations bill after House and Senate conferees agreed that the city could not use its own money for abortions for poor women and dropped tougher mandatory minimum sentencing for drug traffickers.

By maintaining current law prohibiting city funding of abortions, conferees avoided a confrontation with President Bush, who threatened to veto the bill if it restored the city's right to pay for abortions for poor women. The bill now goes to the president, who is expected to sign it.

The House twice in the past week rejected the appropriations bill over the abortion issue, despite strong efforts by city officials and key representatives to gain passage.

"It is the eleventh hour. There is no alternative," said Rep. Julian C. Dixon (D-Calif.), chairman of the House D.C. appropriations subcommittte, in urging House passage last night despite his objection to the abortion restriction. "It is a compromise that is necessary at this point in time. It is one I am not happy with."

The sentencing amendment, added by Sen. Phil Gramm (R-Tex.), would have imposed tougher mandatory sentences. The proposed sentences ranged from 10 years without parole for a first offense of selling drugs to a minor or for using a firearm during drug trafficking, to a life sentence without parole for a third offense.

City officials had argued that the District already has a mandatory minimum sentencing law on the books and that the new minimum would be an addition to already severe sentences. If the proposal had been adopted, conviction on a first marijuana offense could have resulted in a 20-year minimum sentence without parole, said Luis Burguillo Jr., the city's associate director for federal and congressional affairs.

"It's excessive," Burguillo said.

Ultimately, conferees decided they did not have enough information on the effect of the proposal or its cost.

"This a major impact on the system here without hearings, arbitrarily to go to 10, 20, 30 {years}," Dixon said.

Gramm defended the plan, saying it is needed to stem rising violence in the city.

"We ought to commit to strong law enforcement and mandatory sentencing, considering the crime wave that has struck the District." Sen. Brock Adams (D-Wash.), chairman of the Senate D.C. appropriations subcommittee, said there were no good estimates on what such a change would cost the city. The vote by Senate conferees to abandon the proposal was 3 to 2.

City officials said they were pleased that it appeared the appropriations bill would finally be signed by Bush, although they were disappointed with the decision on abortion, which has become an annual fight on the Hill. Last year, Bush vetoed the D.C. appropriations bill twice because it included city funds for abortions for poor women, and ultimately Congress continued the prohibition it had enacted two years ago.

The conferees also subtracted $2 million from $30 million in federal funds that had been added for drug treatment, schools and other purposes.

A total of $1 million was cut from school funding. The money would have been spent on pay raises for teachers, and another $1 million was deleted from the extra appropriation for the Department of Administrative Services.

The $3.9 billion spending bill for fiscal 1991 includes a $430 million federal payment, which provides the city with about 13 percent of its budget.