Talks at averting strikes by London bus workers in a row over an Olympic bonus are to be held on Monday.
Members of the Unite union are planning 24-hour walkouts next Thursday and on July 24, just a few days before the opening ceremony.
The union is seeking a bonus of £500 for each of its 20,000 members at 20 bus companies for working over the Games period.
Peter Harwood, chief conciliator at conciliation service Acas, said: "We are pleased to confirm that further Acas talks will take place on Monday July 2 between Unite and the bus operators."
Meanwhile, a leading train company told union leaders it would not renegotiate a pay deal as workers prepared to vote in a strike ballot in a row over an Olympic Games bonus.
The Rail Maritime and Transport union (RMT) wants more money for its members at South West Trains (SWT), pointing out that other transport firms were paying a bonus to cover the period of the Games. Union members will start voting next week on whether to take industrial action.
SWT warned the RMT that it will not be renegotiating the pay deal it said was agreed four months ago which already covers the period of the Games, accusing the union of reneging on the agreement. The firm said a "significant" pay increase of 4.75% was agreed in February, specifically including arrangements during the Games period.
A spokesman said: "We are disappointed the union has decided to press ahead with this unnecessary ballot. We negotiated a deal with the RMT in good faith and we have stuck to it. We want the union to be 100% clear about our position: we will not be renegotiating our agreement that already covers Olympic arrangements."
RMT leader Bob Crow said: "South West Trains have now resorted to sheer bullying of the workforce in their desperate attempts to force our members to work longer and harder during the Olympics for nothing in return while the company makes a killing for its shareholders from the increased Olympics services.
"RMT is campaigning for a massive yes vote for action in this ballot to force the company to see sense and to demonstrate the level of anger this issue has generated across the service. Other train operators throughout the London area have shown that they are prepared to play fair with their staff over the Olympics. Instead of resorting to threats and bullying, South West Trains should do the same."