Warriors chief executive Mick Watson was delighted to have secured the star centre's services until at least the end of 2006.
"This will be Clinton's year," Watson told the League Correspondent.
"If you look around the NRL, there's a long list of high quality centres but Toopi is there. That was never more evident than in the test between the Kiwis and Kangaroos when he scored three tries."
Warriors general manager Spiro Tsiros said the club wanted to sign Toopi well before the season began to allow him to concentrate on playing rather than contract negotiations.
"His skill on the field speaks for itself, as does his devotion to the club," Tsiros said.