The presidents of the American and National leagues denied yesterday that there are substantive plans for the leagues to buy the Oakland A's, operate the club this season and then sell it to a Washington owner.

But, Lee S. MacPhail of the AL and Charles S. (Chub) Feeney of the NL said such proposals occasionally have been circulated among club officials and could be raised again at the leagues' joint meeting next week.

Both presidents said their leagues are interested in exploring ways to return baseball to Washington, but emphasized there presently are no formal or master plans to be presented to the 26 clubs at their March 24 meeting in Tampa.

Their comments came in reaction to a story in yesterday's Chicago Sun-Times, saying owners in both leagues have agreed "in secret and collective action" to buy the A's, operate them this season and sell to a Washington owner.

As in various past proposals, the club would have to switch to the NL because the Baltimore Orioles have AL territorial rights over Washington. If that were to happen it would create two 13-club leagues and might involve limited interleague play.

The Sun-Times also said a two-man interleague committee was being selected to approach A's owner Charles O. Finley with the idea. The league presidents said no such committee is in the works.

Contacted at home, Finley said MacPhail had called him last week to ask if he would be interested in such a proposal. Finley said he wouldn't sell his club to anyone and plans to continue to operate it in Oakland.

MacPhail replied that "I have talked to him about a number of matters almost every other day, including the possibility of his selling his club.

These were personal conversations and I am not authorized by the league to negotiate any kind of deal. At times he has intiated these conversations himself. Charlie has said to me on occasion, 'Help me find a buyer for my club. I'm going to be desperate in a year.'"

Last summer Finley tried to sell three star players for $3.5 million, saying he needed the money to rebuild his once-championship club. When baseball commissioner Bowie Kahn nullified the sales, Finley brought suit for $3.5 million, claiming the commissioner had exceeded his authority.

A decision is still pending in that suit and Finley used yesterday's devolopments as another chance to attack Kuhn and his authority while a federal judge determines if Kuhn exceeded his powers in an arbitrary manner.

"Everything's coming to the front now," Finley charged. "When Bowie Kuhn canceled my deals, it was part of his plan to keep (together) as good a team as he could for Washington. He's saying, 'To hell with Charlie Finley' so he could sell to someone in Washington.

"In no way am I going to pull his chestnuts out of the fire," Finley said of Kuhn's well-known desire to return major league baseball to Washington. Finley told The Washington Post last month that he would like to move the A's here as an NL team if the leagues would buy out the remaining 10 years of his lease at Oakland Coliseum.

The potential Washington owner mentioned by the Chicago newspaper was Edward N. Cole, retired president of General Motors, who lives in a Detroit suburb. Cole could not be reached for comment yesterday but in the past he has expressed interest in a Washington franchise.

A shift of the A's to the NL and eventually here has been promoted by some club executives since it would solve the so-called Washington problem in the San Francisco-Oakland area where both clubs are experiencing financial difficulties.

Three baseball executives reached yesterday - Dick O'Connell of the Boston Red Sox, Bill Veeck of the Chicago White Sox and Ed Fitzgerald of the Milwaukee Brewers - said they knew nothing of any suggestions for a league take-over of the A's.

O'Connell and Veeck said they would not be surprised if some club officials brought the subject up at the meetings, particularly since most of the agenda deals with possible realignment of divisions.