He gets a $4 million signing bonus, $8 million next year, $12.5 million in 2010 and $13.5 million in 2011. Dempster has a 2012 option for $14 million.

"I never thought sitting there negotiating over 50-something million dollars would be such a hard thing to do," Dempster said. "Ultimately what it comes to, you have to think: What are our chances to win a world championship? I think given as close as we've gotten the last few, I just thought this is where I want to be."

News of the impending deal was first reported by FOXSports.com's Ken Rosenthal.

Dempster was 17-6 with a 2.96 ERA for the Cubs last season, then became a free agent after making the switch from the closer to starter.

"It was imperative that we kept him in house," Cubs general manager Jim Hendry. "No doubt in our minds that Ryan would have exceeded this deal on the streets in three or four weeks from now, the way the market is for starting pitching. Ryan was committed. From Day One he told us he wanted to stay. And it was a priority for us to try and get it done before we got too far down the road in the winter."

Dempster said he's not worried that he might have gotten a bigger or better deal elsewhere if he'd spent more time on the market. He said there were no other firm offers immediately, but there were several teams that showed interest, including Atlanta, the Mets, the Yankees, Toronto and the Dodgers.