TEST star Andrew Fifita is set to finish his NRL career at Cronulla, after signing a four-year contract extension to stay at the club until 2022.

The front-rower, who turns 28 next week and was already signed until next year, is now locked into the Sharks until after his 33rd birthday.

"It's a really exciting time for myself and my family, to secure my future for another five years," Fifita said.

Sharks coach Shane Flanagan believes Fifita is a player he could potentially build a team around in the years to come.

"We've all seen the growth in Andrew off the field and his football has gone to a new level as well over the last couple of seasons," Flanagan said.

"He is a match-winner, as we saw in the grand final and then again in the first Origin game, and to have him here at the club for a further five years is very exciting."