The Colorado Rockies have grown fond of Aaron Cook's sinker, his ability to pitch deep into games - when healthy - and his clubhouse presence.

So, the team finalized a new contract with Cook on Tuesday, one that guarantees him an additional $30 million over three seasons.

"He represents the character and integrity we've developed in the organization," Colorado general manager Dan O'Dowd said. "We felt it was the appropriate time to get this done."

Cook already was set to earn $4.5 million next year under an option the Rockies exercised in October. His new deal adds a $2.5 million signing bonus and salaries of $8.75 million in 2009, $9 million in 2010 and $9.25 million in 2011.

The Rockies and Cook have an $11 million mutual option for 2012 with a $500,000 buyout.

Cook went 8-7 with a 4.12 ERA in 25 starts for the NL champions this season. He went on the disabled list in mid-August with an oblique injury and returned for Game 4 of the World Series, when Boston beat the Rockies 4-3 to complete a sweep.

The 28-year-old right-hander is 36-35 with a 4.47 ERA in six major league seasons, all with the Rockies.

"I don't think he's hit his full potential yet," O'Dowd said. "He's got as good of a sinkerball as there is in the game. He works quickly and throws a lot of strikes. He's a 200-inning guy when healthy. But even more, we like him as a person. He's a tremendous person. He's a count-on guy. I don't think you can ever have enough character."

O'Dowd thinks the Rockies have a strong rotation anchored by Cook and left-hander Jeff Francis.

"Jeff and Aaron are two important guys in the fold," the GM said. "We're going to have some young pitchers that need to be brought along, and there's not two better guys to do that."

O'Dowd didn't want to address where his attention will turn next, now that Cook's deal is completed.

"We're still trying to build our club," O'Dowd said.

Colorado recently re-signed catcher Yorvit Torrealba and reliever Matt Herges. The team also traded second baseman Jamey Carroll to the Cleveland Indians for a player to be named and lost free-agent second baseman Kaz Matsui to the Houston Astros.

Cook's new deal includes escalators based on 200 or more innings pitched each year from 2008 through 2011. If he is traded, the value for remaining years in the deal rise by $1 million each.