Mobil Oil Corp. President William P. Tavoulareas this week released three internal Mobil documents that support his claim that the oil company was reimbursed for funds used to buy out one of the partners in his son's shipping firm.

The documents were released by the company to answer a charge by Rep. John D. Dingell (D-Mich.) that Mobil's president may have misused corporate funds to enrich his 30-year-old son, Peter.

The Washington Post reported on Nov. 30 that the president of Mobil five years ago set up his son as a partner in the London-based shipping firm, Atlas Maritime Co., which has since done millions of dollars in business operating Mobil-owned and other ships.

Atlas was formed in 1974.

Atlas senior partner, George D. Comnas, a former Exxon executive, resigned less than a year later.

Comnas has said that Mobil's president, Tavoulareas, offered him a Mobil consulting contract worth $90,000 over three years in exchange for his departure from Atlas.

According to the Mobil documents, the contract was in the form of "principles of agreement" between Mobil Shipping and Transportation Company and Comnas. The terms of the agreement included the payment of $75,000 in consulting fees over three years plus $9,300 for three first-class airline tickets from Athens to New York.

One of the Mobil documents, an April 15, 1976 letter from Mobil to Comnas says that "Atlas Maritime Company has agreed to reimburse us with respect to any amounts we shall pay you."

Mobil officials said that the documents show conclusively that no Mobil funds were used to help Tavoulareas' son increase his ownership interest in Atlas.

Securities and Exchange Commission officials, who requested and received some Mobil records in 1977 during a brief inquiry into Mobil's relationship with Atlas, were not given the documents released this week by Mobil, an SEC official said.

At the time, Mobil officials said that "Mr. Tavoulareas (Mobil's president) does not participate in decisions as to the relationship, directly or indirectly, between Mobil and Atlas," according to a Jan. 4, 1979, letter to the SEC from Mobil's vice president and corporate counsel, George A. Birrell.

SEC enforcement officials reportedly have begun interviewing new witnesses familiar with the Mobil-Atlas relationship.