HEADLINE STOCKS-Some U.S. stocks on the move on July 8

(Updates to add Hess, DynCorp, MSC Software, Freeport, ARYx Therapeutics, Steak n Shake, AIG, Air Products, DryShips)

NEW YORK, July 8 (Reuters) - Some U.S. stocks on the move on Wednesday:

ALCOA INC (AA.N)

The aluminum company is scheduled to report its quarterly results after the closing bell, unofficially kicking off the second-quarter earnings season.

Shares of the Dow component fell 2.2 percent to $9.20.

GOOGLE INC (GOOG.O)

The Internet search company is planning to launch a personal computer operating system in the second half of 2010, a move that takes direct aim at Microsoft's (MSFT.O) Windows product. [ID:nL8468341]

Shares of Google rose 1.6 percent to $402.87 while Microsoft, a Dow component, fell 0.9 percent to $22.34.

MSC SOFTWARE CORP MSCS.O

The company has agreed to a $360 million buyout by private equity firm Symphony Technology Group and private investment firm Elliott Management Corp. [ID:nN07337927]

Shares gained 11 percent to $7.48.

FAMILY DOLLAR STORES INC (FDO.N)

The company reported third-quarter results that beat expectations.

Shares gained 11 percent to $30.80.

TRACTOR SUPPLY CO (TSCO.O)

The company forecast second-quarter earnings above expectations and raised its full-year outlook. [ID:nBNG406026]