Two team sources confirmed reports that Theo Epstein has reached agreement with the Cubs on a five-year contract and will officially leave the Red Sox before the end of the week.
The deal is believed to be worth $15 million with Epstein receiving what amounts to a $3.5 million signing bonus.
The Red Sox will receive compensation from the Cubs in the form of cash or minor league prospects. Epstein and the Red Sox also have discussed what staff members he would be allowed to take with him to the Cubs.
Epstein's contract with the Red Sox ran through the 2012 season. But owner John Henry did not stand in the way of his seeking a promotion when Epstein made it clear that he preferred to leave. There is still a slim chance that Epstein could have a change of heart and elect to stay with the Sox. But one source the process is so far along now that a reversal is unlikely.
Epstein's top assistant, Ben Cherington, has been operating as the de facto general manager for several weeks and is expected to swiftly be named as his replacement.
A 37-year-old New Hampshire native and Amherst graduate, Cherington has been with the Red Sox since 1999 in a variety of positions.
Cherington was one of the team executives who filled in for Epstein during his break from the organization in 2005 and early 2006 because of a dispute with team president Larry Lucchino.