Talks between British Airways Plc and trade unions aimed at averting more strikes at Europe's biggest airline have been adjourned until next week, the independent arbitrator said yesterday.

"Talks have been adjourned until Tuesday," said a spokesman for UK arbitrator Acas. "Some progress has been made," he added.

An unofficial strike by about 250 BA check-in staff last weekend at London's Heathrow airport, the world's busiest international hub, disrupted the travel plans of tens of thousands of people. The walkout was triggered by the introduction of an electronic "clock-in" swipe card for staff.

BA chiefs and officials from three unions representing check-in workers have held two rounds of talks in front of Acas after direct talks between them broke down.

The unions, however, said little progress had been made during the marathon session, and called on BA Chief Executive Rod Eddington to attend a meeting with unions immediately.

"With some regret we have not advanced the process much further," said Bill Morris, general secretary of the Transport and General Workers Union, in a statement.

"We now stand adjourned and my union will be seeking an immediate meeting with Rod Eddington. We are desperately anxious to avoid a catastrophe for the airline," he added.

BA cast the talks in a positive light. "It was a long night of constructive discussions... Some further progress has been made. BA remains keen to keep talking in a positive way," said a BA spokeswoman.

Hopes for a resolution were soured somewhat overnight by the threat that BA engineers might go on strike.

An official close to the discussions downplayed the seriousness of the engineer dispute, however, saying the talks with engineers were at "a much lower level."