Independent oil producers won another round as the Senate continued work on the "windfall profits" tax yesterday.

Voting 57 to 37, the Senate shelved a proposal by Sen. Patrick J. Leahy (D-Vt.) that would have kept independent producers from taking the depletion allowance -- a fancy income tax deduction -- on income earned when oil exceeded certain base prices.

Leahy intended that independents ought not get a tax break on top of a windfall, the windfall being the extra money they will earn as oil price controls are removed. But the Senate disagreed.

Earlier, the Senate also voted to exempt the independents from paying any of the windfall tax it is levying on other producers.

Both votes shifted the burden of the tax toward the major oil companies on the theory -- which is disputed by a minority of senators -- that the independents, who do most of the nation's oil exploration, need a tax incentive to continue.

Together the two incentives add up toabout $25 billion for independent producers over the next decade: 10 billion from the windfall tax exemption and 14.6 billion from the depletion allowance on windfall profits. This is in addition to a $16 billion exemption for independents' "stripper," or low-production, wells that was recommended by the Senate Finance Committee in the bill now before the Senate.

The vote on the Leahy amendment was a setback to efforts by the Carter administration to stiffen the Senate version of the tax, which, in its current form, would raise about $158 billion by 1990. This is $20 billion more than the Finance Committee proposed but still far less than the $277 billion version of the tax approved by the House and favored by the administration.

During the debate on his amendment, Leahy said that a depletion allowance on windfall profits for independent producers (major oil companies no longer receive such an allowance) would amount to an outright government subsidy. Oil state senators countered that the amendment would "tax away the incentive" to explore for oil in this country and, in the words of Sen. John Tower (R-Tex.), cause "dancing in the streets of the OPEC capital cities."

At one point Sen. Lloyd Bentsen (D-Tex.) noted that Vermont produces large quantities of asbestos and marble, both of which qualify for depletion allowances. Bentsen accused Leahy of knowing more about maple syrup than oil production and added testily, "The one thing I know most about asbestos is that it causes cancer."

Late yesterday, the Senate began consideration of a Republican amendment to limit the percentage of the nation's gross national product that can be taxed by the federal government, which would in effect provide a tax cut of $39 billion in 1981.

Senate Budget Committee Chairman Edmund S. Muskie (D-Maine) charged that the GOP amendment would "subvert the [congressional] budget process, hold out hollow promises to the American people . . . and plunge the budget into irretrievable deficit until 1981," and said he would seek to block the amendment on grounds it would breach previously approved budget limits.