The D.C. Stadium-Armory Board, which runs Robert F. Kennedy Stadium, is considering leasing the stadium to Redskins owner Jack Kent Cooke, who in turn would be responsible for operating and subletting the stadium, sources say.

The board comprises Mayor Marion Barry, National Guard Maj. Gen. Calvin Franklin and Stuart J. Long, a lawyer and Capitol Hill restaurateur.

Sources told The Washington Post this week that, under the plan, Cooke would pay $500,000 a year to lease the stadium. He then would operate all services and sublease the stadium to tenants such as the Washington Federals of the U.S. Football League and Team America of the North American Soccer League.

In addition, sources said, the mayor and Long are hopeful Cooke, with his considerable financial resources and clout, would be instrumental in helping the city obtain a major league baseball team.

Cooke said recently the prospect of owning a baseball team here was appealing.

The city, meanwhile, was studying the costs of constructing luxury boxes similar to facilities in Texas Stadium.

In addition, other additional seats might be added. The cost of such a project would be between $7 and $8 million. Three years ago, a similar plan, privately financed, did not get off the ground.

The stadium, which opened in 1961, cost $19.8 million in principal and $800,000 in total interest payments to build. The money was repaid in 1979 by a combination of federal and city funds.

The title is currently held by the Department of Interior, but there is a bill--introduced by Del. Walter Fauntroy (D-D.C.)--pending before Congress that would give title of the stadium to the city.

According to leases signed by the USFL and NASL teams, a major league baseball team would get priority dates in the spring. The city has been without major league baseball since 1972.

The Redskins currently rent the stadium from the Stadium-Armory Board for 12 percent of gross ticket revenues, or about $800,000 a year. The lease, which was signed in 1960, expires in 1990.

"The Redskins have a lease through 1990," the mayor said through a press aide. "There have been discussions regarding a renewal, but no decisions have been made."

It was learned, however, that these discussions have intensified recently and the mayor wants very much to get an agreement with Cooke.

"I know there was interest in that plan," Gen. Franklin confirmed yesterday. "I don't know of any formal discussions recently. I know Mr. Cooke wanted to improve the stadium, as do we. But that interest was expressed some time ago."

Cooke was out of town and could not be reached for comment.

Long, who sources say is close to the negotiations, said this week there have been no recent discussions between Cooke and the board about the lease.

Long noted that the Interior Department still maintains the title to the stadium. "We can't negotiate anything," he said. "It's silly to talk to them about anything until we can offer them something.

"What can I offer the guy? We're still tenants. If we're an owner, that changes it."

R. Robert Linowes, vice chairman of the board of the Washington Federals who have a lease with the Stadium-Armory Board through 1990 at the same 12 percent rental as the Redskins, said: "We don't know what the (Cooke) deal is; but we'd like to take a look at the proposal."