DETROIT (AP) _ The founder of Domino's Pizza announced Friday he will retire and sell a ``significant portion'' of his stake in the company to a Massachusetts investment firm.

Bain Capital Inc. manages more than $500 million, with investments in more than 75 companies. One of its managing directors is Mitt Romney, the son of former Michigan Republican Gov. George Romney

``At the age of 61, reflecting on my life and the goals I have yet to fulfill, I have decided to retire from active involvement in Domino's Pizza and devote more time to my charitable endeavors,'' Monaghan said in a statement.