The Securities and Exchange Commission yesterday made public a list of questions it had asked Arthur Andersen & Co. about how the accounting firm would handle a series of "hypothetical" transactions involving illegal foreign payments.

In the unusual documents, the SEC also disclosed Arthur Andersen's answers.

According to several commission sources, the questionnaire was sent to Andersen because many of its clients were involved in cases brought by the SEC several years ago alleging questionable foreign payments.

Because of this, the commission asked Andersen specifically about its reporting on foreign payments to satisfy itself that the Chicago-based auditing firm had reformed the reporting measures of its foreign offices.

Apparently the answers satisfied the commission that the firm indeed had reformed the reporting of questionable payments transactions.

In replying to the questions, Arthur Andersen -- which has 142 offices in 44 countries -- stressed that its answers, like the questions, were "hypothetical."

Among the questions asked of Arthur Andersen was how the auditor's overseas offices would handle:

Kickbacks to purchasing agents by the foreign subsidiary of a client;

Two sets of books by the subsidiary;

Payoffs through a Swiss bank to officials of a foreign country in violation of the foreign exchange laws of that country.

In another, unrelated matter also involving Arthur Andersen, the SEC disclosed the settlement of two administrative actions against the firm, one of them growing out of 10-year-old audits done by the firm.

In that case, the SEC alleged that Mattel Inc., the toymaker, and its former management had overstated its profits for 1971 and its losses for 1972. The company itself settled with the SEC in 1974, and several of its senior executives subsequently were convicted of criminal offenses in connection with the scheme. The case against the accounting firm remained outstanding until now.

In the other case involving Arthur Andersen's accounting practices, the SEC alleged that the firm failed to uncover accounting errors that overstated income between 1971, and 1975 of a client, Geon Industries Inc. of Woodbury, N.Y.

In settling the two long-standing cases, Arthur Andersen agreed to publication of the SEC findings of "deficiencies" in the firm's audits of the two companies. At the same time, the accounting firm neither admitted nor denied statements or conclusions in the SEC's report.