Century 21 Takes On a Co-Investor : Real estate: A partnership of entertainment executive Robert W. Pittman buys a stake of 10% to 15%. He will be company’s CEO.

In an unexpected move Tuesday, the new owner of Century 21 Real Estate Corp. said it has taken on a co-investor who will become chief executive of the Irvine-based international residential real estate business.

Hospitality Franchise Systems Inc., a New Jersey hotel franchiser, completed its acquisition of Century 21 for $200 million in cash and stock Tuesday and immediately announced that it had sold a stake in the real estate company to entertainment executive Robert W. Pittman. Pittman, 41, chief executive of Time Warner Enterprises and its Six Flags Entertainment unit, will take over as head of Century 21 on Nov. 1.

He will succeed 63-year-old Richard J. Loughlin, Century 21’s president and chief executive since 1981 and a 22-year veteran of the real estate franchising operation. Loughlin will become president emeritus under a two-year contract.

Pittman said Tuesday that his Pittman Holdings Partnership paid cash for a stake of 10% to 15% in Century 21. He would not discuss details of the private purchase. Hospitality and Pittman acquired the real estate company from Metropolitan Life Insurance Co. of New York.

Pittman, who started in business as a 15-year-old part-time radio disc jockey in his native Mississippi, said he intends to use his background in marketing and brand-name exploitation to move Century 21 into a new era of real estate franchise sales.

Pittman declined to offer specifics, but he did say he sees a future in which a large chain like Century 21 can provide franchises with “one-stop shopping” services where home sellers and buyers can get financing, title insurance and other real estate services. Companies providing these services would pay Century 21 for access to its 6,000 offices.

Pittman joined the Warner organization in 1979 to develop the Movie Channel. He is credited with creating the MTV music channel. In 1983, he became chief operating officer of MTV Networks; he was appointed chief executive of the multichannel network in 1985. Pittman was also executive adviser to the late Steven J. Ross, Warner Communications chairman during the 1989 merger with Time Inc.

Pittman and two longtime associates at MTV and Six Flags formed Pittman Holdings Partnership in June.