Los Angeles ? Jay-Z, who has declared himself retired from his rap career, now has a new job to occupy his time — president and chief executive of the Def Jam record label.

The appointment, rumored for months, was finalized with an announcement Wednesday by Antonio “L.A.” Reid, the chairman of Island Def Jam Music Group.

Officials at the label declined to discuss terms of the agreement. But a source familiar with the deal said the rapper signed a three-year contract valued between $8 million and $10 million.

The ultimate value of the deal depends on whether the multi-platinum rapper can meet revenue and market share incentives, the source said on condition of anonymity.

The rapper, whose “The Black Album” was nominated for three Grammys, will take the helm Jan. 3. He will also continue to run Roc-A-Fella records, which he co-founded with Damon Dash in 1995 after early efforts to obtain a record deal sputtered.

Def Jam, which owned 50 percent of Roc-A-Fella, also announced Wednesday that it had wholly purchased the rap label, whose acts include the 10-time Grammy nominee Kanye West, Cam’ron and Beanie Sigel, who recently received a one-year prison sentence in Pennsylvania on gun and drug charges.

Def Jam acquired the remaining stake in Roc-A-Fella for about $10 million, the source said. A dozen Roc-A-Fella employees were laid off as a result of the buyout, said Def Jam spokeswoman Laura Swanson.