The opposition Labor Party coalition held Prime Minister Menachem Begin's ruling Likud party to a standoff last night in Israel's national election, but Begin appeared well positioned to form another government and remain in power, according to projections based on incomplete returns.

Computer projections showed that the Labor Party, bolstered by a surprising show of support from Israeli Arabs, won 49 seats in the 120-set parliament, or Knesset. The Likud also won 49 seats, according to the projections.

The pivotal religious parties, which are in the present Likud coalition, were projected as taking 14 seats. they theoretically could join either Likud or Labor as coalition partners, but have indicated they are likely to side with Begin. This key role would give them added leverage to advance their causes, including stricter observance of religious laws and continued settlement in the occupied West Bank and Gaza Strip.

Labor Party leader Shimon Peres nevertheless chaimed that the vote projections, based on incomplete returns of the 1.9 million Israeli voters, was a "great victory" for the Labor Party and would restore unity to a divided Israel. The projections were based on counts in 561 of the 4,300 precincts.

Begin also claimed election victory at 3:30 a.m. in his crowded election headquarters in Tel Aviv, declaring, "I will form the next government for the next 4 1/2 years, and don't forget the half year." He was referring to the fact that his term was due to expire in November before he was forced in January to call for an early election to avert a collapse of his government.

"We in the Likud have today a solid majority of Knesset member," Begin said, apparently referring to his coalition and the prospects of retaining the religious parties in his alliance.

Begin mocked Peres for claiming a victory three hours earlier, saying, "Why was he in such a hurry?"

The prime minister said he would try to "speed up" the process of forming the new government.

Former foreign minister Moshe Dayan's Telem Party, which had been forecast to gain three seats, captured one placed in the parliament, which will be filled by Dayan, who headed the ticket. Dayan said he would like to join a government, but cautioned,

"We'll wait until the big parties turn to us. We do not want to betray our ideals."

Dayan, who was in the Begin government before he quit in a policy dispute with Begin, has indicated during the campaign that he would be more inclined to join with the Likud in forming a coalition, however.

The Likud in the 1977 election won 43 parliament seats but formed a coalition with the religious parties will look to the National Religious Party, which in a stunning defeat dropped by nearly a third to eight seats, and to the Agudat Yisrael and Poalei Agudat Yisrael religious parties bloc of six seats in an effort to form a new goverment with the combined total of 63 seats, two more than needed to form a majority.

Foreign Minister Yitzhak Shamir, a member of the Likud, declared last night, "If these figures remain, we will form a new government. Of course, we can form a coalition. A government is a government, and it doesn't matter what its majority is."

Shamir also indicated that Likud may try to add two seats won by Religious Affairs Minister Aharon Abu-Hatzeira's new Tami Party.

Abu-Atzeira said last night he would prefer to join a Likud coalition, and he predicted that Labor will find it impossible to form a government.

In theory, the Labor Party could form a coalition majority by picking up support from the few small parties that won seats, but it would also have to win over the Tami Party, the religious parties and receive the support of the Democratic Front for Peace and Equality, also known as RAKAH, which is a communist ticket. RAKAH won three or four seats, according to projections, and it would not likely be asked to join either Labor or Likud as part of a government.

One of the most significant aspects of the election was the strong swing by an estimated 200,000 Arab voters who live in Israel proper for Labor, and away from the communist ticket. Forty percent of the RAKAH vote went for Labor, compared with only 15 percent in 1977.

Another major development in the election was the shattering defeat of the many small parties, which normally place one or two members in parliament. Only 13 of the 31 parties that fielded candidates in the election won enough votes to gain a seat or more, indicating that many Israeli voters who normally vote for small liberal parties turned to Labor as a vote against Likud.

In what sounded like a victory statement but fell something short of it, Peres told an exuberent crowd of supporters at party headquarters that the vote represented a "great historic moment for the nation of Israel and our party."

"We're talking about two different citizens, two different ways," Peres said in an obvious reference to the ethnic divisions that have marked the the campaign. "Our way received a mandate to guide them . . . We will do our best to heal the wounds so we will not be a nation of ethnic groups but we will be united."

He said he thanked the Arab voters "for showing their trust."

The Labor Party appeared to face a dilemma. If it turns to the Agudat Yisrael bloc in an attempt to form a coalition, it probably would lose the support of the small, leftiest parties with which it would be expected to ally itself, such as the Citizens' Rights Movement and the Shinui Party, a remnant of the defunct Democratic Movement for Change.

The small liberal parties are adamently opposed to religious influence in the government, and are also not likely to compromise on the issue of the future of the occupied territories.

Under Israel's electoral system, voters cast ballots for parties and not individual candidates, and they are not permitted to cross vote across lists of candidates submitted by each party.

As a result, the voters elect members of parliament, with seats apportioned approximately 18,500 votes per parliament seat. The elected members of parliament, in turn, choose the government after intensive and sometimes lengthy coalition negotiations.

The election followed the most bitterly fought and violent campaign in Israel's 33-year history, one in which rhetorical excess and physical clashes between partisan supporters not only became a central issue, but also were widely held to be responsible for a dramatic shift in public opinion toward the Labor alignment in the final weeks of the contest.

Labor was trailing Likud 38 to 28 percent in polls conducted in the middle of the month when public attention overnight became riveted on a pattern of violence at Peres campaign rallies. Young Likud supporters, most of them Sephardim of Asian or African origin, dirupted Labor Party speeches, attacked Peres backers and vandalized cars and houses adorned with Labor Party posters. Police brought charges against more than 200 Likud backers.

Labor strategists immediately seized the issue, sending their own film crews to record incidents of bullying and broadcasting them on nightly paid potilical advertising.

Peres branded the hooliganism as "Beginism," equating it with "Khomeinism," terms that became trigger words for futher incitement to many disaffected Sephardic Jews.

The campaign violence underscore deep ethnic divisions in Israel, which, while not new, have been more pronounced than in past elections here and have caused considerable embarrassment to a country that prides itself on its homeogeneous and idealistic character.

Reflecting Israel's traditionally volatile and moody electorate, this campaign was roller coaster of public opinion, sending Begin and Peres alternately to the heights and depths of the ratings.

Beset by rampant triple-digit inflation and interministerial squabbling, the government watched its approval rating plummet to the point where for two years it never exceeded 20 percent, while critical public opinion never fell below 80 percent. In january, when Begin's fractious Cabinet averted certain collapse by calling for an early election, Labor was predicted to win a victory of 58 seats versus 20 for Likud. Never before had an opposition party in Israel enjoyed such an electoral advantage over a ruling party on Labor did over Likud.

However, Begin, who had appeared paralyzed by his government's failures, seemed to under a metamorphosis this spring when the campaign began. Seizing on national security as an issue to drown domestic issues on which he would have been vulnerable, the prime minister initiated an aggressive policy in Lebanon, culminating with the downing on April 28 of two Syrian helicopters used to support Syrian attacks on Israeli-backed Lebanese Christian forces.

The resulting crisis over Syrian deployment of surface-to-air missiles in Lebanon, followed by the spectacular June 7 Israeli Air Force raid on Iraq's nuclear reactor, dominated the campaign and obscured issues upon which Peres had hoped to dwell.

The party tried with some success, to go on the attack and bait Begin into making an intemperate defense of the Israeli military operations in Syria and Iraq. The object, Labor strategists said, was to frighten undecided voters aways from the Lukud.

While the Labor tactis stopped the Likud's momentum dead in its tracks and began to move Peres up in the polls, Labor Party official feared that it was a case of too little, too late to overcome the Likud's advantage of having more potential coalition partners in the partiament.

In another move, widely regarded as a desperation attempt to counter the debilitating effects of internal Labor Party fighting, Peres dropped former chief for defene minister and replaced him with his arch-rival, former prime minister Yitzhak Rabin. But some Labor officials said any beneficial effects of that move would not be felt for 10 days, too late for the election.