Union leaders are hopeful of reaching a basic agreement during talks aimed at averting January strikes at the UK's busiest airports, including Heathrow.
Union leaders have called off the first of three strikes, set for 7 January, that threatened to paralyse some of the UK's busiest airports.
The Unite union is planning two 24-hour strikes, and one 48-hour stoppage at seven airports across Britain.
The decision comes after airport operator BAA called for last minute talks to resolve concerns about its plans to alter workers' pension rights.
The meeting comes after talks between management and unions over a proposed change to pensions collapsed last week.
The strikes would affect all of BAA's seven UK airports, including Heathrow, Gatwick, Stansted and Edinburgh.
A union negotiator told the BBC that he was hopeful the basis of an agreement could be reached by the end of the day.
The union is planning 24-hour strikes on 7 and 14 January from 0600 GMT, and a 48-hour strike on 17 January also from 0600 GMT.
The strikes, if they go ahead, would affect all of BAA's seven UK airports at Heathrow, Gatwick, Stansted, Edinburgh, Glasgow, Aberdeen and Southampton.
Airport operator BAA has said 1.3 million passengers would be affected.
Airport operator BAA has said 1.3 million passengers would be affected.
Optimism
Outline terms
The planned industrial action is in protest at the closure of final salary pension scheme to new workers by BAA 's Spanish owners.
The unions involved, Unite and the Public and Commercial Services Union (PCSU), had called for three strikes.
Monday's talks were restarted at the request of BAA, raising expectations that the airport operator may be prepared to shift its position over the closure of the pension scheme.
They were scheduled to take place for 24 hours starting at 0600 GMT on 7 and 14 January, and 48 hours from 0600 GMT on 17 January.
The negotiations, at an undisclosed location, will be held with leaders of Unite and the Public and Commercial Services Union (PCSU).
The planned industrial action was in protest at the closure of final salary pension scheme to new workers by BAA 's Spanish owners, Ferrovial.
A negotiator for the PCSU, Paul Smith, told the BBC that they hoped they would see the basis of an agreement by the end of today.
Union officials said that the first strike was called off after progress was made during Monday's talks.
Stephen Nelson, BAA's chief executive, is understood to be leading the negotiations with union representatives.
The outline of a deal over the pension scheme has been reached and will now go to union delegates for ratification.
BAA welcomed the union's optimism and expressed hope that it would be reflected in the talks.
Should it be approved, then the strikes on 14 and 17 January would also be called off.
Unite represents about 6,000 airport workers employed by BAA, including firefighters and security staff, without whom the airports cannot operate.
Under the terms of the plan, BAA and the unions would meet to jointly consider the future of the pension plan, and call in independent experts to assess its financial state.
Its members also include maintenance and clerical staff.
Limit impact
Baggage change
Unite represents about 6,000 airport workers employed by BAA, including firefighters and security staff, without whom the airports cannot operate. Its members also include maintenance and clerical staff.
Last week both sides spent several hours in talks that ended without a breakthrough.
Last week unions and BAA executives spent several hours in talks that ended without a breakthrough.
The trade unions have insisted the decision to close the final salary pension scheme must be reversed before the industrial action can be called off and negotiations on the future of the scheme are held.
The trade unions had insisted the decision to close the final salary pension scheme must be reversed before strikes were called off and negotiations on the future of the scheme were held.
Brendan Gold, Unite national aviation officer, will lead the union negotiators at Monday's talks.
Brendan Gold, Unite national aviation officer, had earlier said that the unions had avoided taking industrial action over the Christmas holiday period to limit the impact on the travelling public.
He said the unions avoided taking industrial action over the Christmas holiday period but stressed that workers were determined to secure the future of the pension scheme for all members.
However, he stressed that workers were determined to secure the future of the pension scheme for all members.
The union said 1,946 members had voted to strike, with 1,108 voting against direct action.
The date of the first strike, 7 January, is the day when rules on the amount of permitted carry-on baggage are due to change, which was already expected to cause some confusion in airports.
Passengers will be allowed two items of carry-on baggage, but only if they are at an airport that has bought a new type of 3D scanner.
