President-elect Ronald Reagan indicated today that his Cabinet will not include William E. Simon and George P. Shultz, two prominent veterans of the Nixon and Ford administrations who had been early favorites to return to Washington.

Reagan said that Simon definitely will not have a Cabinet post. Friends of Shultz have told Reagan that Shultz does not want a Cabinet job, the president-elect said.

Reagan said he wants to confirm with Shultz that the former treasury secretary is no longer interested in a Cabinet post. That check appeared a formality, however, since Reagan also told reporters that he has come very close to final choices for several Cabinet posts without talking directly to Shultz.

"I have some firm leanings in certain directions," Reagan said, "but I'm still willing to hear cases that anyone might want to make for others." Reagan made these remarks to reporters in a brief question-and-answer session at Santa Monica airport, where he landed after a flight from his mountain ranch north of Santa Barbara.

The apparent elimination of Simon and Shultz from the Cabinet sweepstakes raises new questions about what sort of team the president-elect hopes to assemble. Speculation had centered on prominent Republicans who served in the Nixon and Ford administrations, a group that some of Reagan's oldest backers have referred to contemptuously as "retreads."

Reagan still may turn to Nixon-Ford veterans, but some Republicans interested in the selection process expressed hope today that he also will seek new faces. "What you ought to seek is a kind of healthy mix" between newcomers and people with Washington expereience, Reagan said today.

With Shultz and Simon out of the running for the State Department and Treasury posts, former general Alexander M. Haig and longtime Reagan confidant Casper Weinberger emerged as leading contenders for those two jobs, respectively.

Word that Simon was no longer a candidate for the Reagan Cabinet first appeared in today's New York Daily News. Simon told reporter James Weighart that he had asked Reagan in a telephone conversation Wednesday to withdraw his name from consideration for "personal reasons."

Reagan generally confirmed Simon's account that he had withdrawn his name from consideration, but other sources close to Reagan said "a good deal of scrambling had gone on to save face for Simon."

According to well-placed sources, Simon had pressed his case too hard and perhaps asked for too much authority over economic policy. Reagan and his inner circle, these sources said, knew that Simon was popular not only with the wealthy businessmen around the president-elect, but also with the most conservative elements in the Republican Party, so Reagan was anxious to put a polite appearance on Simon's elimination from the Cabinet sweepstakes.

However, other sources with a credible claim to inside information, though further removed from Reagan's inner circle, said that Simon really did withdraw voluntarily when he realized that former president Gerald R. Ford, Repulbicans on the Senate Finance Committee and others were sniping at him and would make his life uncomfortable even if he got a Cabinet job.

Simon had pushed his candidacy to return to the Treasury Department since the first Cabinet selection meeting of Reagan's California advisers after Election Day. His candidacy was supported forcefully by Justin Dart, a California businessman and longtime Reagan confidant, who suggested that Simon's name be the only one recommended to Reagan for treasury secretary.

Reagan, returning to Los Angeles after three days' vacation at his ranch, told reporters he telephoned Simon Wednesday afternoon because he had received a message that Simon was no longer interested in joining his Cabinet.

However, Simon's and Reagan's accounts of their conversation differed on one point. Simon told the Daily News that Reagan had said that both he and his "kitchen cabinet" favored Simon for treasury. Reagan declined today to say that he had favored Simon, saying only that Simon had been under consideration.

One Reagan adviser said today that Simon's version of his withdrawal from consideration was "a face-saving gesture on Simon's part. He felt the office was slipping away from him and moved early to say he didn't want it anyway."

The Washington Post reported Wednesday that Simon had suggested that Reagan move quickly after the election to appoint key Cabinet members, including himself. A proposal to recommend that course of action was offered to Reagan's "kitchen cabinet" by Dart, who is close to Simon, but it was rejected.

Simon is said to have believed that unless he was nominated quickly, opposition would mount and he would never get a job in the Reagan administration. A Reagan adviser on economic affairs said today that there was "very strong opposition to Simon, especially from former president Ford," who was upset at the prospect of Simon in Reagan's Cabinet. Ford reportedly believes that Simon was an abrasive figure and poor team player in his administration.

In remarks to the Daily News Thursday and to WCBS radio in New York today, Simon said he was reluctant to uproot his family and move to Washington. Simon, currently a financial consultant to a Saudi oil sheik, also complained about new conflict-of-interest and financial disclosure requirements.

"Public service has become so unattractive, indeed ugly, by really a combination of factors -- the press, the conflict-of-interest laws, the 'ethics in government' business -- that it seems that anybody who has any expertise in any subject is deemed to have a conflict if he put in an allied activity in Washington," Simon told WCBS. (Simon did not return to a telephone call from The Washington Post.)

He also complained that "we seem to wish to savage public officials to such an extent that it's made just an ugly sense of being."

As for Shultz, Reagan said: "I have been told by people close to him that he feels" he does not want to be in the Cabinet. "He's had that experience and I certainly understand."

Reagan said that both Simon and Shultz "couldn't have done more" to be helpful to him.

Reagan wore a blue western shirt, faded jeans and brown boots as he and his wife, Nancy, traveled by Marine Corps helicopter from his ranch to Los Angeles. He carried a small briefcase and a large flashlight.

He said that he would be calling some of his Cabinet choices over the weekend or next week.

Others who had been mentioned as possible contenders for Treasury secretary include Alan Greenspan, chairman of the Council of Econmic Advisers under Ford; Charles E. Walker, deputy secretary of the Treasury under President Nixon; Walter Wriston, chairman of Citicorp, and Lewis Lehrman, a New York financier who is now a favorite of the New Right Leaders who had been high on Simon.

CBS News, meanwhile, quoted unidentified sources tonight as saying that once Reagan decides on his entire Cabinet, he will take the unusual step of asking the Senate to hold confirmation hearings prior to his Jan. 20 inauguration. That way, said the account, the new Cabinet would be ready to begin work immediately after the inaguration although the full Senate would not vote on the nominations until after the swearing in.

On another subject, Reagan said today it was "a good indication" that Soviet President Leonid I. Brezhnev this week expressed a willingness to start new Soviet-American talks on arms limitations.