Oxford United are in ongoing talks to bring Peterborough striker Tyrone Barnett back to the club, according to chief executive Mark Ashton.
Barnett arrived on loan at the Kassam Stadium in September and scored six goals in 14 games for the U's.
Ashton told BBC Radio Oxford a transfer fee had been agreed, but added that they faced competition from clubs in the Championship for the 29-year-old.
"I'd suggest it's one of the largest fees this club's ever paid," he added.
"The challenge we have is that there are a number of other clubs in higher divisions - including the Championship - that are trying to persuade Tyrone to go there.
"We have to line up the club, the agent and the player and that can be a challenge. It's not about the funds, it's about identifying the right player and then pushing on all three fronts and this is one of the transfers we're continuing to push on."
Ashton ruled out a move for Nottingham Forest striker Dexter Blackstock, insisting the 28-year-old - who started his career at Oxford's academy before joining Southampton - was "not on our list".