Sen. Howard H. Baker Jr. cashed in his chips yesterday and former president Gerald R. Ford looked for a chair at the table, as the remaining players in the Republican presidential nomination game celebrated what they said were victories in the latest round of primaries.

Ronald Reagan said he was glad to have won Vermont. George Bush said he was relieved and pleased to have won Massachusetts. And John B. Anderson said he was elated to have finished a close second in both states on Tuesday.

Baker, who was a fading fourth in the New England contests, closed down his campaign, joining colleague Bob Dole on the casualty list of those who were thrown by the whirling Republican merry-go-round.

Ford, talking to reporters in Lauderhill, Fla., described the GOP contest as "wide-open" and once again hinted that he would like to play.

In an ABC television interview aired yesterday, Ford said there was a "50-50" chance he would enter the race, saying he would decide within about two weeks.

It was learned that the three top officials ousted last week from Reagan's campaign had gone to Los Angeles to discuss with Ford the possibility of his becoming an active candidate in the late primaries.

John P. Sears, Reagan's former campaign manager, political director Charles Black and press secretary Jim Lake were not available for comment, but were reliably reported to have a meeting scheduled with Ford when he returns to Rancho Mirage on Monday.

There were informed reports that Ford would decide on his candidacy on or about March 18 -- the day of the key Illinois primary and just days before the filing deadlines for primaries in such states as Maryland, Michigan, California and Ohio.

The former president's name was entered Tuesday by the secretary of state in the May 6 primary in Baker's home state of Tennessee -- making that the first place where Ford's name might appear on the ballot.

Ford's intentions remain in doubt. He told reporters in Flordia that the three-way split in the votes in Vermont and Massachusetts was "a clear indication to me that there is no consensus" on a preferred candidate among those actively seeking the GOP nomination.

But two Republican veterans close to Ford said they were skeptical that the former president would find the "massive display of vocal, out-front support" one of them said Ford would need to become an avowed contender.

That phrase was used by Stuart Spencer, a top official in the 1976 Ford campaign, who said "I kind of doubt" that such a draft will be forthcoming.

Former secretary of defense Melvin R. Laird, another Ford intimate, said that while it would be "very easy" to find a number of Republicans eager to have Ford run, "it would take support from almost all the people who are in the race right now to take the nomination from Reagan. Otherwise, the numbers just don't add up."

Last night in Charleston, S.C., Reagan indicated that he expects Ford to become a candidate.

Asked his response to Ford's "teasing" about entering the GOP race, Reagan replied: "I think he takes it seriously. I don't think he's teasing at all."

Reagan also said that if the Republican contest comes down to himself versus Anderson, it would offer a clear philosophical test. Reagan praised Anderson for his "courage" but said that the Illinois congressman was the candidate who strayed farthest from "Republican principles."

Anderson and Bush were sounding like anything but stalking horses for Ford yesterday, and such key governors as James R. Thompson of Illinois, Richard A. Snelling of Vermont, Otis R. Bowen of Indiana and Pierre S. (Pete) du Pont IV of Delaware all disavowed any willingness to lead or join a draft-Ford movement at this time.

But du Point commented that "the phone bills for calls on this subject the last few days would pay off a good part of the national debt." And a senior party official said "the Ford thing is moving real fast."

Anderson took his suddenly successful campaign from Massachusetts to Connecticut, vowing to embarrass Bush in the March 25 primary in the state that the Massachusetts-born Texan considers his second home.

Reagan flew from California to Charleston to resume campaigning for Saturday's South Carolina primary contest against Bush and John B. Connally. Reagan is favored in the race, which Connally has made the make-or-break test of his expensive but now financially strapped effort.

A poll published in today's Charleston Evening Post showed Reagan far ahead, with 32.8 percent, followed by Bush at 10.2 percent and Connally at 9.8 percent. The poll supported the view of many party pros that Reagan's stock was rising as voting neared in the Palmetto State's first primary this Saturday.

Bush, campaigning in Melbourne and Daytona Beach, Fla., said he was "very encouraged" by his narrow win in Massachusetts, declaring that it ended the talk that he had been finished by his loss to Reagan in the previous week's New Hampshire primary.

Bush campaign leaders James A. Baker III and David Keene said Howard Baker's withdrawal would help Bush consolidate moderate suport in Florida and Illinois, but both aides said Reagan should be considered the favorite over Bush in Tuesday's Florida contest, highlight of a day that also includes voting in Georgia and Alabama.

With Reagan considered the favorite in the upcoming "southern tier" and the condition of Connally's candidacy uncertain following those tests, the March 18 Illinois primary is now regarded as the crucial test, not only in positioning the active candidates but in influencing Ford's decision on whether to enter the race.

The Illinois primary consists of a "beauty contest" preference poll and the separate election of delegates, none of whom is identified on the ballot by candidate affiliation.

A Chicago Tribune poll taken Feb. 22-24, just before the Reagan victory in New Hampshire, had Bush ahead with 38 percent, Reagan 21 percent, Anderson 14 percent, Baker 7 percent, and Connally 3 percent. A Chicago Sun-Times poll on Feb. 24 had Bush leading Reagan, 33 to 25 percent, with Baker at 8 percent, Anderson 7 percent, Connally 6 percent and Rep. Philip M. Crane, still clinging to his longshot chances, at 5 percent.

While even some key officials in the other campaigns appeared unaware of the fact yesterday, Anderson suporters noted that in Illinois, as in Vermont, any registered voter, Democrat, Republican or independent, may ask for a Republican primary ballot.

Interviews with voters leaving polling places in Vermont and Massachusetts, where independents, but not Democrats, were allowed to vote in the Republican primary, showed unmistakably that Anderson was the main beneficiary of the crossover vote,

But Thompson, Illinois' Republican governor, sounded skeptical when he said in an interview that "it remains to be seen whether Anderson will sell as well in Illinois as he did in Massachusetts and Vermont. I assume the increased media coverage will boost his stock a bit in Illinois, but he wasn't very well known outside his own district, and he's always been more liberal than his district."

Keene, Bush's national political director, predicted that his candidate will win Illinois, adding that Anderson "will be lucky to get 10 percent of the vote."

Both Bush and Sen. Paul Laxalt of Nevada, national chairman of the Reagan campaign, said yesterday that they did not anticipate the entrance of Ford as an active contender.

Snelling, the Vermont governor who tried to launch a draft-Ford drive last fall before joining Baker's ill-fated campaign, said that he did not believe another effort in that direction would be "constructive" at this time.

While saying that "the Republican Party can lose the election if it does not find a rallying point," Snelling added that the uncommitted governors "have no capacity to direct events in presidential politics unless they are active early . . . The governors who have called me about Ford this week are the same people who didn't think they should move last year."

Iowa Gov. Robert D. Ray, another Baker backer with close ties to Ford, said he wanted to "let the dust settle for awhile" before deciding what to do next, and similar statements came from Republican governors in Tennesse, Michigan, Indiana, Delaware and Wisconsin.

Barring a surprise, the Republican contest appears likely to remain fluid until Illinois votes and Ford decides -- about the same day -- whether to enter the game.