The Pompey Supporters Trust has taken a "significant step" towards completing its takeover of the stricken south coast club after exchanging contracts with the administrators PKF.

The two parties have exchanged contracts pending a high court case on 10 or 11 April that will rule on whether the former owner Balram Chainrai is required to sell Fratton Park to the fans' group for the £3m that it believes it is worth rather than the £10m he has valued it at.

By exchanging contracts, any uncertainty over whether PKF might change its mind at this late stage or surrounding a rival bid by a consortium led by the football financier Keith Harris is removed.

"We can confirm that the administrators have now exchanged contracts with the PST for its purchase of Portsmouth Football Club," said the club administrator and PKF partner Trevor Birch. "Completion is conditional only upon the court sanctioning the sale of Fratton Park and the Football League transferring the membership share."

The Football League has made it clear on three occasions that it will only sanction a sale to the trust. Last month, fresh questions emerged over the protracted deal to deliver the club into the hands of supporters who have watched a succession of overseas owners twice take the club into administration as it has slipped down the Football League.

Birch initially recommended the rival Harris bid to creditors, because it would have represented a marginally better return and would not have required a court hearing as it had the blessing of Chainrai.

But he made the decision to proceed with the PST bid after the Football League reiterated that it was the only one it would consider and said the club would be liquidated if the matter was not resolved by the end of the season.

The valuation of Fratton Park will be decided in the high court on 10 or 11 April and the PST remains confident that its bid will succeed. A spokesman said that the exchange of contracts was a key milestone: "This is a significant moment. We have been working towards this for the last 12 months and see this as a significant step in the move to community ownership and a brighter future for Portsmouth Football Club."