A Philadelphia-based company that operates concessions in 11 national park areas has agreed to buy five Lake Powell marinas and a river-raft tour company from Del Webb Corp. for $77 million.

ARA Services Inc. has agreed to buy the Wilderness River Adventures tour company and marinas at Bullfrog Basin, Hite Crossing, Dangling Rope and Hall's Crossing in Utah and at Wahweap in Arizona, said ARA spokesman John Gribbin.He said the deal must still be approved by the National Park Service, which grants concessions in areas it administers - including the Glen Canyon National Recreation Area.

He said ARA plans "status quo" operation of the marinas and does not plan to change administration there.