The federal judge in Philadelphia who has jurisdiction in matters involving the National Hockey League and the World Hockey Association was informed last month that discussions between the league on "matters of mutual concern" have begun, The Washington Post has learned.

Although it is premature to conclude that a merger or amalgamation of the two leagues, similar to the one last year that resulted in the disbanding of the American Basketball Association and the entry of four of its teams into the National Basketball Association, is in the offing, sources in both the WHA and NHL indicated that the possibilities are being discussed.

An attorney for the WHA confirmed yesterday that Judge A. Loen Higginbotham of the U.S. District Court for the Eastern District of Pennsylvania has been informed that conversations are taking place.

Judge Higginbotham issued the 1974 consent decree approving the settlement of an antitrust suit between the WHA and NHL over the NHL reserve clause and issuing guidelines for the relationship between the two leagues.

He retains jurisdiction over and supervision of that subject matter.

"About all I'd be willing to say is that the court has been informed that there are discussions between the WHA and the NHL," Harold Kohn of Philadelphia, counsel to the WHA, said yesterday. He would not elaborate on the nature of the discussions or who was taking part in them.

Judge Higginbotham was informed on Feb. 11 that the two leagues are talking, Kohn said.

"It was very informal, more of a courtesy to the court than anything else," Kohn added.

" . . . There are no formal proceedings before him with respect to these conversations.I'd like to avoid any speculation beyond that."

John Ziegler, NHL chairman of the board, NHL counsel Edwin Rome and Judge Higginbotham refused to comment.

There is a widely held opinion in the pro hockey community that some amalgamation of the two leagues, or an agreement to tend the bidding for talent that has driven the average salaries of players under contract to NHL teams up to $86,000 and those of WHA contractees up to $55,000, is imperative if the severe financial problems confronting both leagues are to be solved.

The NHL owners signed a wide-ranging five-ytar collective bargaining agreement with the NHL Players Association on Oct. 6, 1975, that is auto- matically terminated in the event of a merger.

The NHL Players Association threatened antitrust litigation in 1973 unless the two leagues agreed to refrain from merger discussions.

NHL president Clarence Campbell, one of several voices within the 59-year-old league, has consistently and adamantly opposed any merger with the 6-year-old WHA.

Because three of the 18-team NHL and four of the 11-team WHA are Canadian; the laws and courts of two countries would be involved in any merger agreement, making it extremely complicated.

At least one NHL team president confirmed yesterday that discussions of a merger with the WHA have taken place within the past two weeks.

WHA president Bill MacFarland predicted yesterday, "There will be only one major league in pro hockey in the near future, no later than the 1978-79 season."

MacFarland declined to comment specifically on current discussions or the recent report to Judge Higginbotham, and acknowledged that major obstacles to a merger exist, but said he was hopeful one could be worked out.

"Every time in the history of pro sports there has been this situation (two rival leagues), the end result has been one league, either through merger or the collapse of one," he said.

"The ABA and NBA managed to get the best markets into one league, and I think that's going to happen in hockey. I don't know how or when, but it will happen, either through a merger or the collapse of the WHA or NHL. And I don't see either league collapsing at this point.

"I don't think there's anybody in the WHA who would not be amenable to a merger and payment of initiation fees as the ABA did, as long as it's reasonable," MacFarland said.

He acknowledged "big problems to overcome." He cited opposition within the NHL and by the NHL Players Association, and the possibility that "An antitrust suit by any one player in either league independent of the players associations could throw an agreement out of kilter."

But he said he did not view any of the obstacles as insurmountable.