By Caroline Valetkevitch

NEW YORK, Sep 25 (Reuters) U.S. stock index futures pointed to a higher market open on Monday as crude oil's break below a barrel lifted optimism about spending and profits, but investors will look to data on existing home sales to gauge the extent of the U.S.

economic slowdown.

Shares of computer maker Hewlett-Packard were up about 2 percent in European trading after the company said late on Friday Chairman Patricia Dunn has resigned effective immediately.

The news boosted the stock about 1 percent to .46 in electronic trading on Friday. For details, see ID:nN22225663.

The National Association of Realtors' report on existing home sales for August is due at 10 a.m. (1400 GMT). Economists in a Reuters survey forecast a median 6.18 million annualized unit total versus 6.33 million annualized units in July.

Concern that the fallout from a slowing U.S. housing market could stymie economic growth and hurt corporate profits has gripped sentiment in recent sessions.

S&P 500 futures were up 3.40 points, above fair value, a mathematical formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract.

Dow Jones industrial average futures up 29 points, and Nasdaq 100 futures were up 4.75 points.

''Right now the market is pointing higher, with oil prices dipping,'' said Peter Cardillo, chief market analyst and chief strategist at SW Bach and Co. But, he said, ''the real market mover will be the housing data, with investors worrying about how much the economy is eroding.'' Oil dropped on abundant supplies in top consumer the United States, easing worries about inflation and the need for higher interest rates. U.S. crude fell 74 cents at .81.

In merger news, Superior Energy Services Inc. on Monday said it agreed to buy Warrior Energy Services Corp. in a cash and stock deal. ID:nWNAS7521 Profit news will include quarterly results from drugstore Walgreen Co..

On Friday, stocks fell as investors worried that the economy will slow more sharply than expected, prompting them to sell shares of big industrial companies such as heavy equipment maker Caterpillar Inc..

Stocks had risen sharply since the start of the month, with the S&P 500 index and the Dow average attempting to mount their biggest September advance in eight years, as crude oil prices dropped roughly 15 percent.

REUTERS SBA HT1730