Sosa and the Cubs have reached a contract extension worth about $72 million, a pair of sources familiar with the negotiations, speaking on the condition they not be identified, told The Associated Press on Thursday.
The Cubs announced Friday that Sosa had agreed to a four-year extension, although financial terms were not released. A news conference was set for later in the day at the Cubs' spring training facility in Mesa, Ariz.
Sosa's been one of biggest baseball stars since his home run derby with Mark McGwire in 1998, which finally brought baseball out of its post-strike slump. McGwire hit a single-season record 70 homers that year, while Sosa finished with 66.
Over the past three years, he's hit 179 homers and batted .305. His 50 homers last season led the majors, and he joined McGwire and Babe Ruth as the only players with more than two 50-homer seasons.
Sosa, who is currently in the last year of a $42.5 million, four-year deal, began asking for an extension almost a year ago. When negotiations didn't appear to be getting anywhere early last season, he gave the Cubs a midsummer deadline to either sign him to a long-term contract extension or trade him.
The Cubs came close to letting him go, but a deal with the New York Yankees fell through. With the tension over the negotiations affecting his production, Sosa announced after the All-Star break that he wanted to stay in Chicago and would block any trades.
Despite the distractions, Sosa ended up with one of his best seasons. He hit a career-high .320 and drove in 138 runs. He also hit 38 doubles and drew 91 walks.
Though offseason negotiations got testy at times, the contract extension has been expected since Sosa arrived at spring training Feb. 26. His agents and Cubs president and general manager Andy MacPhail said they were optimistic they could work something out, and hoped it could get done before opening day.
Sosa seemed to sense something was coming, too. Moody and sullen last summer when he was the subject of trade talks, he's been downright chipper this spring.
``He has been great this spring. He probably senses that something's on the horizon,'' Cubs manager Don Baylor said earlier this week. ``And it's not a trade or free agency.''
Sosa himself has been unusually quiet the past few days - except for the leadoff solo homer he hit in the second inning Thursday in the Cubs' 2-0 victory over the Arizona Diamondbacks in a split-squad game. That gives him four for the spring.