House Speaker Thomas P. (Tip) O'Neill Jr. yesterday fueled growing speculation about a presidential bid by Sen. Edward M. Kennedy (D-Mass.), saying if Kennedy decides to run he will have the support of the New England congressional delegation.

"I don't think he [Kennedy] could be denied the Democratic nomination if he were to run," the Massachusetts Democrat told reporters at his daily news conference.

"I'm sure they [Carter supporters] realize that no member of the New England delegation could be of much help if Kennedy were to announce," he added later.

The timing of his comments added to the political flurry Kennedy started last week when he announced that his mother, Rose, and his estranged wife, Joan, had given approval to a presidential campaign. Their possible opposition had been seen as a potential obstacle.

O'Neill, a longtime ally of the Kennedy family, previously has said that "If Kennedy were to run, Carter wouldn't get the nomination, in my opinion." But he has never implied that New England's congressional delegation would desert the president for Kennedy. Only 241 of the 3,331 delegates to the Democratic convention will be from the region in 1980, but all of the area's primaries are among the nation's first.

The speaker said he doesn't have "any reason to believe" that Kennedy will be a candidate.

He sidestepped questions about who he would support in a Carter-Kennedy battle, saying President Carter had not yet asked for his support. "I support the Democratic Party every day of the week . . . I'm going on the basis that the nomination is his [Carter's] without any serious problems," O'Neill said.

Meanwhile, the White House yesterday tried to place itself above presidential politics. Press secretary Jody Powell told repoters that in coming weeks Carter will be far more concerned about ratification of the SALT II pact and passage of his energy legislation package than about reelection.

In a news briefing dominated by questions about Kennedy, Powell said:

"We are going to do everything in our power to prevent the premature injection of presidential politics from detracting from these concerns . . . We can't spend the rest of the year playing games with presidential politics and we're not going to do it."

Powell then pleaded with reporters to focus on SALT and the energy issue. When he read yesterday's newspapers, he said, "I got the impression it was 1980 and that we had just passed New Year's Day; not Labor Day."

Powell had no comment on O'Neill's remarks, and he continued to evade questions about what was discussed during a lunch Carter and Kennedy had last Friday. Asked if Carter and Kennedy had discussed the Democratic nomination, Powell replied, "I doubt it.'

The Friday meeting occurred only hours after Kennedy's announcement about his wife and mother.

For months, draft-Kennedy groups and political leaders around the country have waited for a sign that Kennedy, who repeatedly has said he isn't a candidate, would challenge Carter.

Last Friday's announcement was viewed by many as the signal. "I was talking to a number of congressmen last night," said Lou Gordon, director of a national draft-Kennedy group. "The question over Kennedy was no longer 'if' in their minds, it was 'when.'"

Senate Minority Leader Howard H. Baker, Jr., who is expected to be a Republican presidential contender, said Kennedy's statement "was tantamount to an announcement."

Senate Majority Leader Robert C. Byrd (D-W. Va.) declared, "I think it's a pretty clear sign that he's keeping his options open."

Baker predicted a Kennedy-Carter fight would lead to a "wholesale political bloodletting."

"I don't think Carter will roll over and play dead," he said. "I think Kennedy will have to take it (

he nomination from him."

Democratic National Committee Chairman John C. White, who long has tried to discourage talk of a Kennedy candidacy, agreed. "It would be a mighty struggle," he said of a Carter-Kennedy fight. "But it would divide the party and probably make the nomination worthless."

As a party loyalist, Kennedy has long been thought to be opposed to challenging Carter, leading to speculation that he would enter the race only if the president bowed out or it if appeared Carter had no chance of reelection.

Kennedy added to this speculation when, according to a report in The Boston Globe Saturday, he told two New York Democrats, Gov. Hugh Carey and Sen. Daniel P. Moynihan, tht he would make up his mind about running by Thanksgiving. Kennedy's office yesterday said he had set no such timetable.

Kennedy has led Carter by more than two to one in public opinion polls for months. A new ABC News-Louis Harris poll released yesterday reported that 70 percent of those polled believe Carter will not win reelection.

A 56 to 35 percent majority of the 1,493 persons questioned in the poll believe Carter will be unable to win renomination in his own party.