George Steinbrenner and Billy Martin met secretly here today and reached an agreement whereby Martin will resume managing the New York Yankees Monday, United Press International sports editor Milt Richman reported today.

After denying earlier in the day that he would return to the Yankee helm six months early or that he had met with Steinbrenner, Martin last night told the Associated Press in Iowa City, Iowa, that no decision had been reached and that a meeting with Steinbrenner was set for Monday.

Both he adn Steinbrenner are scheduled to play in a pro-am golf tournament there on Monday.

Earlier in the day, Doug Newton, Martin's agent, said his client and the Yankee owner were "supposed to be getting together today (Sunday ) in Columbus."

"I'm down here strictly for scouting purposes," Martin said here before leaving for Iowa City.

The Yankees, who finished a road trip tonight in Arlington, Tex., open a series Tuesday night against Toronto in Yankee Stadium.

According to the UPI report, Bob Lemon, who took over for Martin 11 months ago and guided the Yankees to a world championship, will move into the Yankee front office, with the title of general manager. That post currently is unfilled, but had been ticketed for Lemon next year.

Richman said Lemon is being relieved because of a feeling that the players had lost their initiative and that Lemon had lost control of the team.

The Yankees started today in fourth place in the American League East, seven games off Baltimore's front-running pace.

Reached in Dallas, where he was preparing to direct the Yankees against the Texas Rangers tonight in Arlington, Lemon said, "It's only a rumor so far. If it happens then it happens."

Lemon has three years remaining on his Yankee contract and his main concern, it is said, is remaining in baseball in some capacity.

The UPI dispatch said Steinbrenner and Martin did not have to go over any ground rules today concerning Martin's return, because the Yankee owner did that during a meeting in Yankee Stadium 10 days ago.

According to Richman, Steinbrenner made up his mid to reinstate Martin some time ago, but was upset when a published report of his intention appeared Saturday night.

At Friday night's Yankee-Ranger game, New York slugger Reggie Jackson, who has feuded with Martin, quipped to Texas owner Brad Corbett, "Hey, trade for me! Billy is coming back." Later Jackson said he had been kidding.

Martin has said that Jackson's presence with the Yankees would be no problem for him.

"It's been so long ago," Jackson said. "I don't even remember what the trouble between us was all about. I'm sure George will have all the answers."