LONDON -- U.S. and British diplomats made progress Tuesday in talks with Libyan officials over responsibility for the bombing of Pan Am Flight 103, officials said.

Britain's Foreign Office said the three-way session in London had been useful, but played down reports that Libya had accepted responsibility for the 1988 bombing over the Scottish town of Lockerbie and that a compensation deal had been struck for families of the victims.

In Washington, State Department spokesman Richard Boucher said U.S. officials awaited a comprehensive from Assistant Secretary of State William Burns, who represented the United States at the meeting.

Pan Am flight 103 was bombed on Dec. 21, 1988, killing all 259 aboard and 11 more on the ground.

Britain and the United States are pressuring Libya to comply with U.N. Security Council requirements to accept responsibility for the bombing and provide compensation.

Libyan government lawyers have already set conditions for compensating families of victims a total of $2.7 billion, or $10 million each. The State Department has said it will accept whatever sum the families find acceptable.

But the demand that Libya accepts responsibility has so far proved to be a stumbling block.

Libya is also required to renounce terrorism and disclose all information it has about the downing of the Pan Am jet before U.N. sanctions, currently suspended, can be lifted.

David Ben Ayreah, a spokesman for the families of the victims, said they were not aware of Libya accepting responsibility or of any compensation deal arising from Tuesday's meeting. No one was available for comment at the Libyan Embassy in London.

Former Libyan intelligence agent Abdel Basset Ali al-Megrahi is serving a life sentence for his role the bombing.