THE TEAMSTERS UNION AND THE TRUCKING INDUSTRY WERE REPORTED CLOSE TO AGREEMENT LAST NIGHT ON A NEW THREE-YEAR CONTRACT THAT CARTER ADMINISTRATION OFFICALS DESCRIBED AS BREACHING ITS NEWLY RELAXED ANTI-INFLATION GUIDELINES.

HOWEVER, CHIEF FEDERAL MEDIATOR WAYNE L. HORVITZ SAID AS THE BARGAINERS BROKE FOR A FEW HOURS' SLEEP SHORTLY AFTER 1 A.M. TODAY THAT THEY ARE "AT A VERY TENSE AND DELICATE SPOT." HE ADDED THAT A SETTLEMENT WAS NOT A FOREGONE CONCLUSION ALTHOUGH HE STILL "FERVENTLY" HOPES CAN BE REACHED BY TONIGHT'S DEADLINE.

AS BARGAINERS STRUGGLED OVER FINAL DETAILS OF THE POTENTIALLY PACE-SETTING TRUCKING CONTRACT, SOURCES SID ITS EXPECTED WAGE, COST OF LIVING AND BENEFIT INCREASES COULD AMOUNT TO 30 PERCENT OVER THREE YEARS, ALTHOUGH THERE WERE WIDE VARIATIONSIN ESTIMATES.

THIS IS WELL ABOVE THE ADMINISTRATION'S NOMINAL STANDARD OF 7 PERCENT A YEAR FOR WAGE-BENEFIT INCREASES, BUT IT INCLUDES A NUMBER OF ITEMS EXEMPTED BY THE GOVERNMENT TO KEEP THE VOLUNTARY PROGRAM FROM COLLAPSING UNDER THE WEIGHT OF A GUIDELINE-BREAKING TRUCKING SETTLEMENT.

GOVERNMENT OFFICIALS DECLINED PUBLIC COMMENTS ON THE SETTLEMENT, BUT A SOURCE CLOSE TO THE TALKS SAID SOME HIGH OFFICALS WERE COMPLAINING THAT THE MONEY PACKAGE EXCEEDED THE GUIDELINES BY BETWEEN ONE AND TWO PERCENTAGE POINTS AND THUS BREACHED THE STANDARD. HOWEVER, THE SOURCE SAID THAT AS OF LATE LAST NIGHT THE OBJECTIONS WERE NOT AN OBSTACLE TO SETTLEMENT, WHIN WAS BEING HELD UP BY DISPUTES OVER NON-ECONOMIC ISSUES. The source added that, while the settlementis likely, it is not assured.

The Teamsters' current master freight agreement, covering 300,000 truck divers and warehouse workers from coast to coast, expires at midnight tonight, but bargainers settlement to avoid work disruptions as long-distance drivers prepared for a new work week on Sunday.

Before a breakthrough in the talks late Wednesday, there were wide-spread expectations of a nationwide trucking strike or a series of selective strikes that could prove damaging to the economy and disruptive to the flow of consumer and industrial goods. While walkouts still are possible if a settlement is not reached or if union locals are dissatisfied, strike talk diminished sharply as word of an impending settlement began spreading through the Arlington Hotel where the talks are being held.

Several sources reported that money issues were basically settled, leaving some noneconomic issues -such as rules governing freight carried by owner-operated vehicles-to be settled before the contract could be wrapped up. However, Horvitz said some economic issues sitll remain to be resolved.

They indicated that the settlement is expected to include hourly wage increases of 80 cents in the first year and 35 cents in each of the other two years, amounting to $150 over the life of the contract. The current wage base is nearly $10 an hour.

Until Wednesday, when the government made its latest guideline concessions and the two bargaining teams began exchanging sharply modified wage proposals, the union was demanding $2.35 an hour over three years. The industry was proposing a three-year increase of 85 cents.

While the union yielded more than the employers on wages in the last few days of bargaining, the reported settlement was said by some sources to include the unions' demand for $30 a week in new money for pensions and health and welfare benefits. The companies originally had proposed $13 a week in new benefits.

The Teamsters were reported to have abandoned a proposal for a substantial improvement in cost-of-living increases, which would have increased those payments by roughly 50 percent.

It was unclear whether the contract will include payment of cost-of-living increases on a semi-annual rather than annual basis, as the union was proposing.

Regardless of the precise percentage increase in contract costs, it is apparent that the settlements will fall considerably below the coast of the current contract, which has been calculated at 34 percent by the government but may be as high as 40 percent under recent inflation rates. This could enable the administration to claim a victory even though the numbers do no conform to the 7 percent guideline that was set by President Carter five months ago in urging both pay and price restraintsto curb inflation.

Yesterday's negotiations reportedly started with a new industry offer developed at a late-evening strategy session by top industry officials Thursday night. As Teamster president Frank Fitzsimmons arrived at the hotel yesterday for opening of talks, he was asked about the chances of averting a strike and responded, "We got our fingers crossed."

After being reviewed by the union's 350-member negotiating committee, a settlement must be ratified by the union's 300,000 trucking members. Chances of ratification are enhanced by the fact that it takes a two-thirds vote of the members to reject a settlement negotiated by the union's officers.

The gloom that hung over the talks for weeks, spawning strike jitters throughout the economy, suddenly began to dissipate Wednesday as the government signaled it would relax its stringent guideline interpretations and the bargaining terms moved toward more realistic negotiating positions.

With both sides virtually assured of more guidelines flexibility, they narrowed their wage differences dramatically-from about $1.50 an hour to less than 30 cents-although larger gaps remained in money proposals for pensions and health and welfare benefits. Work rule and jurisdictional issues also remained.

From the start, the government's inflation fighters have been the silent partners in the talks, taking heat from both sides at first for refusing to budge on the guidelines and then relenting in order to prevent one of two unpalatable possibilities: a guideline wrecking settlement or a strike.

Many economists, industralists and union leaders contended that a Teamster settlement far in excess of the 7 percent wage standard would doom the president's voluntary anti-inflation program. The administration itself had mad the talks a critical test, even beyond the trucking industry's normal role in influencing later bargaining in the rubber, electrical and auto industries.

Although the administration had been urging companies to take strikes rather than yield to guideline-busting wage settlements, it was clearly unprepared to let the Teamsters, whose hold on the trucking industry is slipping but still crucial to the flow of food, manufacturing supplies and other economic essentials, go out on a nationwide strike. Carter said in an interview several months ago that he would take swift legal or legislative action to block a national Teamster walkout.

The government's concessions on wage and price guidelines were viewed as critical to a settlement, althoug industry bargainers, facing mounting competition from non-union haulers, kept warning there were limits on how far they could go on without pricing themselves out of the market.

The first concession, agreed to in a meeting of top economic officials Wednesday night, in effect allows the Teamsters a substantial bonus in guideline-approved wages gains for the first year. It discounts, for guideline calculations, 21 cents of the 58 cent hourly cost-of-living increase that Teamsters expect to receive the day after the contract takes effect-about 1.7 percent on top of the union's total compensation base of $12.65 an hour.

This supposedly covers living cost increases in excess of the government's onetime expectation of a 6 percent inflation rate, considerably less than the current double-digit monthly increase in prices. The government earlier contended the entire 58 cents was "new money", chargeable against the guidelines, although the 58 cents covered cost-of-living increases over the last 12 months of the current contract.

To make it easier for trucking companies to pass the cost of the contract on to consumers, itself an inflationary move, the Council on Wage and Price Stability on Thursday softened ist objections to rate increases that the companies are seeking form the Interstate Commerce Commission.