Westfield has ended a dispute over its selection of subcontractors on the White City project in west London.
The developer met M&E union Amicus last week after reports that firms had been asked to retender for work after the departure of Multiplex from the scheme.
Amicus had claimed that cost-cutting had led Westfield to consider bids from firms outside national industry agreements.
However, Frank Westerman, an Amicus regional officer, said this week that Westfield would honour the contracts.
It has also agreed to employ firms registered with the JIB and NIACE, the national agreements between employers and unions covering the M&E and steel sectors.
Westerman said: 鈥淲e have set up monthly liaison meetings with Westfield, and as I understand it all existing contracts will be honoured, although I have written to Westfield for confirmation. It was a very positive meeting.鈥
Westfield took over the building of White City from Wembley contractor Multiplex in August.
Westfield declined to comment.