Reports suggested a deal with Sorin's club Villarreal had been agreed for £2.2 million but Bolton are going to have to step up their wage offer if a deal is to be done.
Meanwhile, Jared Borgetti's move to Al Ittihad has collapsed.
Wanderers had agreed a fee for the Mexican international but the deal has been scuppered after Borgetti rejected the personal terms offered by the Saudi Arabian outfit.
Allardyce told the club's website: "Jared is still our player. Personal terms have not been reached with Borgetti and the Saudi's and for that reason the deal has stalled for the time being."
In other news, Bolton assistant manager Sammy Lee has turned down an offer to become full-time England Under-21 coach.
He will sever all ties with the national team to focus on his role at the Reebok Stadium.