Accounting firm Ernst & Young will pay $9.3 million to settle charges that two of its auditors got "too close to clients on a personal level" and broke rules aimed at ensuring reviews were objective and impartial, the US Securities and Exchange Commission said in a statement on Monday.

"SEC investigations found that the senior partner on an engagement team for the audit of a New York-based public company maintained an improperly close friendship with its chief financial officer, and a different partner serving on an engagement team for the audit of another public company was romantically involved with its chief accounting officer," the SEC said.