Topeka ? Kansas Speedway and a competitor announced Thursday that they are joining forces to push a single proposal for a state-owned casino overlooking a turn at the NASCAR track in Kansas City.

Penn National Gaming Inc., of Wyomissing, Pa., has agreed to buy a 50 percent interest in the speedway casino project from The Cordish Co., of Baltimore. Sale terms were not disclosed.

Cordish and Kansas Speedway’s parent, International Speedway Corp., had proposed a $521 million casino-and-hotel complex at the track. Penn had pursued a $539 million casino-and-hotel complex near the NASCAR track but expects to drop that plan. A 2007 state law expanding legalized gambling allows only one state-owned casino in Wyandotte County.

The speedway-Penn partnership would build and manage the casino for the Kansas Lottery. The state, through the lottery, will own the rights to the gambling, control the computer software and have authority to overrule management decisions.

A state casino review board had scheduled hearings on the competing plans for next week and said it would pick a proposal in early December. ISC and Penn still need its approval, as well as consent from the Lottery and Wyandotte County officials.

“We’re still evaluating everything, but at first blush, it appears to be a very beneficial situation for all parties,” said Ed Van Petten, the lottery’s executive director. “There’s nothing we’ve seen that causes us concern.”

ISC and Penn officials said they’re still working out financial and other details of their partnership. Penn had said it could finance its own proposal without help from lenders, while the speedway-Cordish partnership had said it would borrow $190 million.

The Penn-speedway partnership plans to adopt Penn’s Hollywood theme for its project, rather than use the speedway’s original Hard Rock Cafe theme.

Joseph Weinberg, a Cordish managing partner, said it would focus on plans for a slot machine-and-entertainment complex southwest of Baltimore and “other gaming activities more strategic to us.”