Cereal and food maker General Mills ( GIS) said Steve Sanger is stepping down as chief executive, a post he has held since May 1995. Kendall Powell, 53, was named the new CEO. Powell joined the company in 1979 and was most recently president and chief operating officer.

Sanger will continue as chairman through the end of the current fiscal year in May 2008. Shares of General Mills were down 0.2% at $58.35.

Bristol-Myers Squibb ( BMY) agreed to acquire privately held Adnexus Therapeutics, the developer of a new therapeutic class of biologics called Adnectins. The all-cash transaction has a gross value of $430 million.

Additionally, there's an earn-out provision that could result in Bristol-Myers paying up to an additional $75 million if development and regulatory milestones are met. Shares of Bristol-Myers were slipping 0.1% to $28.97.

Audio equipment maker Harman International ( HAR) guided its first-quarter lower, saying it now expects to miss Wall Street's estimates due to higher research costs.

Harman's forecast change comes after private-equity giant Kohlberg Kravis Roberts and Goldman Sachs ( GS) pulled out of a deal to buy the company, citing a "material adverse change." Shares of Harman were down $4.62, or 5.4%, to $80.38.

Homebuilder Standard Pacific ( SPF) was also trading lower after the company's board eliminated its quarterly cash dividend. The company hopes the move will save $10 million, which will be used to reduce outstanding debt.

Standard Pacific also said it will offer $100 million of convertible notes due in 2012, which Moody's Investment Services later issued a "junk" rating on. The news sent the shares tumbling by $1.03, or 12.7%, to $7.07.

On the positive side, Microsoft ( MSFT) rose 2.6% on the eve of the release of the company's Halo 3 software title. The game, of which 1.5 million copies have been presold, is expected to jumpstart sales of the company's Xbox 360. Microsoft was gaining 74 cents to $29.39.

Gammon Gold ( GRS) said its board has appointed Rene Marion as chief executive, effective Oct. 25. Marion replaces Russell Barwick, who is leaving the position for personal family reasons but will remain a member of the board and a technical adviser to management. Gammon was adding 14 cents, or 1.3%, to $11.30.

Information technology company CACI International ( CAI) was also rising after it agreed to buy Athena Innovative Solutions from Veritas Capital for $200 million in cash. CACI said it expects the deal, which will close by Nov. 1, to slightly boost earnings over the next year. CACI was recently up 43 cents, or 0.8%, to $51.33.

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