ALSO

A spokeswoman for Sunbeam Corp. confirmed that a Securities and Exchange Commission investigation of the company’s 1997 financial statements is now formal. She gave no details.

* American Express Co. said it bought closely held Goldstein Golub Kessler & Co. of New York, the largest acquisition so far in its purchases of accounting companies that focus on small and mid-size companies. Terms were not disclosed.

* Boston Properties Inc., headed by publishing and real estate magnate Mortimer Zuckerman, said it bought the Metropolitan Square office building in Washington for $175 million from a partnership that includes members of the Carr family.

* Gibson Greetings Inc. acquired a majority interest in Australia’s Ink Group, a leading publisher of greeting cards, for an undisclosed sum.