President Carter apparently reported vastly different values for some of his peanut warehouse equipment to tax officials in 1975 and 1976, placing a higher value on the machinery for federal tax credit purposes while reporting lower value to local officials for property tax purposes.

White House officials yesterday conceded that the discrepancies, first reported Thursday night by ABC television, raised "legitimate questions" for which they had no immediate answers.

The White House asked state and local tax officials in Georgia to review the property taxes paid by Carter's peanut warehouse business and to report their findings when the review is completed.

According to the ABC report, in his 1975 federal income tax return the president said that a peanut sheller cost $695,000 and he received an investment tax credit based on that amount. But that same year, the warehouse filed a declaration with Sumter County, Ga., tax officials listing the value of the sheller at $375,000. Carter's local property tax on the sheller was based on the lower amount.

In 1978, according to the report, the president received an investment tax credit for a new peanut loader and elevator that he said cost $367,000. But when the loader and elevator were listed with local tax officials, they were valued at $50,000.

"The broadcast report raises questions to which we do not have answers," White House deputy press secretary Rex Granum said when asked about the different values.

Granum said the White House has aked local and state tax officials in Georgia to reexamine the values Carter placed on the equipment. He said the president will "abide by their findings," meaning that he is willing to pay additional taxes if local officials find the equipment was undervalued.

Whatever the findings of the local officials, the discovery of the disparity in claimed values was clearly a potential embarrassment to Carter, who has portrayed himself as a champion of tax "reform" and denounced various loopholes as benefiting the rich at the expense of the poor.

Shortly after his inauguration, the president made public his 1976 federal income tax returns which showed that, because of the large investment tax credits, he owed no federal income tax that year. But he said then he would voluntarily give the federal government $6,000 because of his "strong feeling" that people in his income bracket should pay some tax.

Granums aid that to the best of his knowledge, Carter did not personally sign the property tax declarations of the equipment's value that were filed in Sumter County. Other White House officials were quick to note that in 1975 and 1976 Carter was campaigning full-time and had turned over day-to-day management of the peanut business to his brother, Billy.

The president's 1975 and 1976 federal income tax returns have been sudited by the Internal Revenue Service, which did not challenge the investment tax credits for equipment that he claimed in those years.

White House counsel Robert Lipshutz said yesterday that some differences in the values reported to federal and local officials should be expected.

Under the federal law, he said, Carter was entitled to an investment tax credit based on the purchase price of the eqiupment. But local property taxes, Lipshutz added, are based on the fair market value of the equipment which would be lower because of depreciation or other factors.

However, Lipshutz conceded that if the figures reported by ABC are acccurate the differences in value "would look too disparate."

Lipshutz said it was not clear to him that the investment tax credits claimed by the president in 1975 and 1976 involved only the equipment cited by ABC or involved other equipment purchased that year by the warehouse.

He also argued that the ultimate responsibility for setting Carter's property taxes rested with the Sumter County tax assessor.

The responsibility and authority rests with the tax assessor's office," Lipshutz said. "They have the last call in it."

According to Frank Belcher, the Sumter County tax commissioner, the county each year sends forms to owners of commercial equipment on which the taxpayers lists the equipment and its value. The values placed on equipment by taxpayers are subject to challenge by the tax assessor, but it could not be learned yesterday whether this was done in Carter's case.

Ronnie Greer, the county tax assessor, could not be reached and officials in his office said they had been instructed by George Ellis, the county attorney, not to speak to reporters. The figures reported by ABC could not be verified independtedly yesterday.

Basing its conclusion on the finding of a tax accountant, ABC said that Carter has either obtained a federal tax saving or more than $36,000 from an inflated investment tax credit or has saved about $8,000 in property taxes by undervaluing the equipment.

In another development at the White House, the president signed a measure extending the deadline for state ratification of the Equal Rights Amendment to June 30, 1982. Without the extension, the deadline would have been next March 22.