Allardyce moved quickly to replace striker Michael Ricketts, who signed for Middlesbrough just before Bolton signed the French duo.
"After an 11th hour approval from the Premier League, we have made two important and crucial signings" Allardyce told the clubs official website.
"With the departure of Michael Ricketts we now have a potent strikeforce with the purchases of Pierre-Yves André and our earlier signing Salva Ballesta who will link up with Henrik Pedersen, Delroy Facey and Youri Djorkaeff
"Im also delighted to have snapped up Florent Laville from Lyon who is a quality centre-half. Our interest became more prominent after the very unfortunate injury to Mike Whitlow who is likely to be out for six to eight weeks
"With the three players signing after the 5:00pm deadline they are unable to play this afternoon. I hope they become as influential as Youri Djorkaeff, Fredi Bobic and Kostas Kontantinidis were last season when they helped us stay in the Premiership"
Striker Andre has joined from Nantes while his French compatriot Laville, a central defender, has joined from Lyon.