BOSTON, Nov 9 (Reuters) - John Henry, who made a fortune in commodities large enough to become principal owner of the Boston Red Sox, plans to close his trading firm to outside investors at the end of the year.

John W. Henry & Co Inc, based in Boca Raton, Florida, “has determined to cease managing client assets effective December 31st, 2012,” the firm said on its web site. “JWH will continue to engage in proprietary trading and research.”