ST. LOUIS (AP) _ Francis J. ''Jack'' Fitzgerald, president and chief operating officer of Monsanto Co., one of the world's largest chemical companies, died at his home Saturday at the age of 58, company officials said.

Fitzgerald assumed the post at the St. Louis chemical company on April 1 and addressed stockholders at Monsanto's annual meeting Friday.

Company spokesman Dana Spitzer said he could not give the cause of death.

Fitzgerald joined Monsanto in 1951 as a cost analyst at a time when the company's annual sales were $600 million. The company, which operates in 120 countries, now has annual sales of $7 billion.

Fitzgerald was a member of the executive committee of the Chemical Manufacturers Association, the industry's leading trade group. He also served in an executive position with the U.S. Chamber of Commerce.

Fitzgerald is survived by his wife Patricia and seven children.

Funeral arrangements are pending, Spitzer said.