The chairmen of the congressional tax committees yesterday agreed to postpone the effective date of tax revision for certain state and local bonds until Sept. 1.

They left undecided, however, the effective dates for many other proposed changes in laws governing tax-exempt bonds and business taxes. The House version of the bill has an effective date of Jan. 1, 1986, while Senate Finance Committee Chairman Bob Packwood (R-Ore.) proposed yesterday making most changes effective Jan. 1, 1987.

Treasury Secretary James A. Baker III endorsed the agreement.

The new agreement between House Ways and Means Committee Chairman Dan Rostenkowski (D-Ill.), Packwood and the ranking members of both committees provides that changes involving state and local bonds would take effect Sept. 1 unless Congress enacts a new tax law before that date.

The postponement specifically excludes industrial revenue bonds, which are issued by governments to finance private projects. The delay is intended to let state and local governments issue general obligation bonds without fear they later will lose their tax-exempt status.

Business groups not only took little comfort from the agreement -- which was narrower than many had hoped for -- but spent yesterday worrying about the many provisions of the Packwood plan that would affect their operations but are not included in the House bill.

The Packwood plan proposes denying the deduction companies take for excise taxes and tariffs they pay. Analysts said it marks a sharp departure from the general income-tax principle that corporations are taxed on their profits, not on their gross income.

"It redefines the corporate tax base to be not just a measure of income, but a measure of income plus taxes," said Harvey Galper of the Brookings Institution.

Several of the industries that would be affected most by loss of the excise tax deduction have been active supporters of the House bill, which does not include the provision. At a meeting yesterday of the Tax Reform Action Coalition, representatives of trucking companies said they will rethink their commitment to the tax package if the excise tax proposal is not changed.

Nick Calio, a TRAC official, said members of the coalition generally were pleased that the proposed corporate rate of 35 percent was one percentage point lower than the level in the House bill. But he said TRAC members from the retailing, trucking, tobacco and alcohol industries had some "concern about a variety of provisions."

According to preliminary analysis, retailers could be harmed by a variety of provisions. Because the plan ends the deductibility of tariffs -- which are relatively high on apparel and textiles -- clothing prices could rise, cutting into sales. Another provision would include tax advantages from installment sales under the minimum tax, and a third could raise taxes on inventories.

Other industries could fare better under the Packwood plan.