Richard Rosenthal, KPMG's chief financial officer since 2002 and previously vice chairman of its tax operations unit, has resigned from his post, company spokesman George Ledwith said Wednesday.

Rosenthal, 48, is retiring, said Ledwith, who would not comment on the reasons for the departure, plans for a replacement or whether Rosenthal has taken another position. While Rosenthal has left his post, he will remain with New York-based KPMG until the end of the year.

Rosenthal's departure was first reported Wednesday by The Wall Street Journal, citing an internal email sent Monday night by KPMG chairman Eugene D. O'Kelly to the firm's partners.

"After a 25-year career with the partnership, Rick has decided to seek an opportunity in the corporate community," O'Kelly reportedly wrote in the email.

The email did not draw a connection between the resignation and investigations of KPMG's tax shelter business by the Internal Revenue Service and the Justice Department. But Rosenthal, who was based at KPMG's Montvale, New Jersey, administrative offices, was active in planning and running parts of that business.

In a 2003 report on the allegedly illegal tax shelters by the U.S. Senate Permanent Subcommittee on Investigations, Rosenthal is one of several KPMG executives mentioned by name as playing a role in devising and marketing the shelters.

Rosenthal's departure follows a shakeup in the leadership of KPMG's tax division in January. The changes included the retirement of Jeffrey Stein, KPMG's deputy chairman. Another top executive, Jeffrey Eischeid, was placed on administrative leave. Richard Smith, vice chairman of the tax services business, was reassigned to new duties.

-- Adam Geller, AP Business Writer