RMT members are currently being balloted over pay

LU managers met with union representatives, including the Rail Maritime and Transport (RMT) union, but no deal was struck.

The RMT is balloting 6,500 of its members over claims a 4% pay rise has been withheld from last April.

LU said once an above-inflation, three-year pay rise offer was accepted, RMT members would be due a pay rise.

The result of the ballot is due later this month.

'Hopeful'

An LU spokesman said the talks had been constructive.

He said: "London Underground again put forward what is a very fair, final three-year pay and conditions offer.

"It is a three-year deal with an above inflation pay rise in each year, plus a cash bonus for all staff if customer satisfaction targets are met or exceeded.

"We are hopeful that we can reach an agreement without the need for industrial action."

The RMT's general secretary Bob Crow said before the talks that they represented a "golden opportunity" to resolve the dispute.

He added: "Our members have been waiting since last April for the pay rise that is due to them, and all we have sought for the last year is the opportunity to negotiate seriously."