Klarman’s Baupost Sells AIG While Adding to Micron Stake

Baupost Group LLC, the Boston-based hedge-fund firm run by Seth Klarman, sold its stake in American International Group Inc. in the third quarter.

Baupost sold 10.1 million shares of the New York-based insurer that repaid a bailout from the federal government, according to a regulatory filing today with the U.S. Securities and Exchange Commission. The shares were valued at $452 million at the end of the second quarter.

Klarman, whose firm had assets of about $29 billion as of mid-September, added 22.5 million shares of Micron Technology Inc. in the quarter, making it his fund’s largest single stock position. Baupost owns 64 million shares of the Boise, Idaho-based producer of semiconductors. Micron reached a 52-week high today after the shares almost tripled this year.

Baupost sold 13 million shares of London-based oil company BP Plc in the third quarter, cutting its holding to 5.6 million shares, the regulatory filing shows.

Klarman, 56, is a bargain hunter who wrote the preface to the sixth edition of “Security Analysis,” a 1934 book by Benjamin Graham and David Dodd that is considered the bible of value investing. He has said he will return some money to investors at the end of the year.