Briefly

TIAA-CREF, the largest U.S. retirement fund, said Wednesday that the Securities and Exchange Commission was conducting an informal inquiry into a relationship between auditor Ernst & Young and two fund trustees.

Ernst & Young, which has audited the fund for seven years, told TIAA-CREF in August of an investment it made in a business owned by trustees William H. Waltrip and Stephen A. Ross. The arrangement might violate federal conflict-of-interest rules, according to a TIAA-CREF filing with the SEC. Ernst’s support of the venture ended last month when the trustees quit.

SEC spokesman John Heine declined to comment.