Liverpool would be his sixth club with the Kop's £20m capping a series of multi-million pound moves.
Coventry paid £6m to Wolves for Keane in 1999 and subsequent deals have seen him go to Inter Milan for £13m, Leeds for £12m and then Tottenham for £7m in August 2002.
Keane has scored 107 goals in 254 games for Spurs and bagged 33 goals in 80 Irish appearances.
Kop boss Rafa Benitez believes Keane will provide his side with much-needed pace up front alongside main striker and Spanish hero Fernando Torres.
