Bolton Council has won a partial victory in a legal tussle with contractors involved in the £15 million Arena at Middlebrook.

But the showpiece sports complex could still go over budget by a six-figure sum.

The council launched action against Manchester-based Cheetham Hill Construction because preparation work on mossy ground was inadequate.

Main contractor Ballast Willisher had to spend several hundred thousand pounds strengthening foundations and claimed the money back from the council.

An independent adjudicator ruled that Cheetham Hill should meet most of this extra cost and the firm agreed an undisclosed payment. But because the adjudicator found Cheetham Hill were not entirely to blame for foundation problems, the council is being forced to find a sum believed to be around £100,000.

Council bosses are optimistic that the majority of this shortfall can be mopped up by money held in a contingency fund to cover any unexpected costs.

But before it can touch the cash stockpile, the council must get the go-ahead from Sports England who are the scheme's main backer to the tune of £11.3 million.

Steve Arnfield, the council's finance director, said: "The majority of the cost should be absorbed by a contingency fund within the existing budget.

"Had the whole adjudication gone against us it might have cost us a few hundred thousand.

"But when you look at the overall cost of £14.8 million, the £100,000 is not a huge sum. This is a very exciting scheme and everything is still on track."

A spokesman for Cheetham Hill said: "Bolton Council are the client so any comment will have to come from them. We are not prepared to comment on this."

The Arena is scheduled to open around Easter next year. Budding Tim Henmans will be groomed on eight indoor and six outdoor courts, and other facilities will include a six-lane running track and basketball court.

The badminton finals of the 2002 Commonwealth Games will also be held at the Arena.