Building understands that Cooper has been offered his old job back as head of Ballast's PFI division after the business is sold. However, sources close to the firm say Cooper, who was promoted earlier this year, is keeping his options open.
One said: "Cooper is being smart. He is keeping his options open until he knows who's buying Ballast. At the moment he's still at Ballast, but is speaking to other companies until the deal goes through."
Ballast has been put up for sale by Dutch parent Ballast Nedam after posting poor results. The business lost £32m in the first six months of the year.
The source added that Ballast's PFI division, which Cooper set up, was the most attractive part of the business. The source said the buyer would be pushing hard with that side of the business, so Cooper was wise to wait to see who bought the firm before committing himself.
Another source said: "Cooper may find that the firm that takes over doesn't suit him or what he plans for the PFI arm. He knows the pressure would be on whoever is in charge of that division."
Ballast was last month forced to issue a statement denying rumours that Cooper was leaving, but it is apparent that this is still a possibility.
Three European firms are believed to be competing for the £160m-turnover business. Among them is German contractor Billfinger Berger – but Hochtief, which owns 48% of Ballast Nedam, is not in the running. Ballast refused to comment on Cooper, or how the sale process was going. Cooper was unavailable for comment.
Ballast Nedam's UK losses contributed to an overall loss of £67m in the six months to 30 June, compared with a £32m loss last year.
Meanwhile, Ballast's marketing director and board member Doug Barrat has resigned for what the firm described as "personal reasons".
Barrat, who had also handled Ballast's media relations and was a board member for nearly 15 years, will continue to work as a consultant for at least two years.