UPDATE 1-U.S. FTC approves Penn National's purchase of Pinnacle with divestitures

(Adds assets to be sold to Boyd Gaming Corp, background)

WASHINGTON, Oct 1 (Reuters) - The U.S. Federal Trade Commission on Monday approved casino operator Penn National Gaming Inc’s $2.8 billion purchase of Pinnacle Entertainment Inc, requiring they divest assets in three Midwestern cities.

The deal is the latest in a series of mergers and acquisitions in the U.S. gambling sector in recent years as companies look to expand their reach, diversify their businesses and take advantage of recent legalization of gaming in some states.

The FTC said the companies should sell casino-related assets in Cincinnati, St. Louis and Kansas City, Missouri, to Boyd Gaming Corp.

The cash-and-stock deal, which would cement Penn National’s position as the leading U.S. regional gaming operator, was announced in December.

Penn National said at the time that after the deal it would operate a combined 41 properties with about 53,500 slots, 1,300 tables and 8,300 hotel rooms in the United States. (Reporting by Mohammad Zargham; Editing by Eric Beech and Sandra Maler)