The decision is in response to O'Rourke's move into main contracting, which was confirmed when it finally bought Laing for £1 in October.
A Bovis spokesperson confirmed that the contractor had written to O'Rourke to inform the firm of the decision. The spokesperson said: "When it became apparent that they were buying Laing, we told O'Rourke there could be a conflict of interest in our future associations with them. This is because O'Rourke has effectively set up in competition with us."
The spokesperson stressed that Bovis would work with O'Rourke under construction management deals with clients that directly contract specialists, such as Stanhope. He said: "If they [clients] want to work with them, we are very happy to work with O'Rourke."
Bovis will now work with existing preferred concrete contractors, such as Byrne Brothers and PC Harrington, when it is main contractor.
One source close to O'Rourke said Bovis had been up front about its decision. The source said: "In fairness to Bovis, they did it above board, they didn't do it secretly. They spoke to O'Rourke officially."
The source said it left Bovis with a restricted choice for concrete specialists. He said: "Without O'Rourke, you only have two or three competitors who could do sizeable concrete jobs."
Rivals said they agreed with Bovis' decision.
One said: "It's a tough marketplace out there and O'Rourke is now a competitor of Bovis."
But one consultant questioned Bovis' decision. He said: "I can't really see Laing Construction as being a main competitor of Bovis right now. Bovis is pitching for bigger work than Laing. It doesn't seem a necessary move for them to make."
