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US STOCKS-Wall St to open modestly higher after earnings, data

* Claims fall less than expected as California backlog continues

* Markit manufacturing slows in Oct, affected by govt shutdown

* 47 S&P 500 companies scheduled to report earnings

* Futures up: Dow 46 pts, S&P 3.2 pts, Nasdaq 2.5 pts

By Chuck Mikolajczak

NEW YORK, Oct 24 (Reuters) - U.S. stocks were poised for a modestly higher open on Thursday, indicating the S&P 500 will rebound from its first decline in the last six sessions, as investors grappled with a host of corporate earnings and muddled economic data.

Initial claims for state unemployment benefits fell 12,000 to a seasonally adjusted 350,000 but were higher than the expected 340,000 claims as California continued to process a backlog of applications caused by computer problems.

Financial data firm Markit said its "flash," or preliminary, U.S. Manufacturing Purchasing Managers Index fell to 51.1, the lowest since October 2012, from 52.8 in September. The survey was conducted partly during a 16-day U.S. government shutdown that economists expect will slow overall U.S. growth slightly in the last three months of 2013.

With a mixed bag of corporate earnings so far, any additional gains in the equity market will likely stem from expectations that the U.S. Federal Reserve will continue its stimulus measures, which have propped up the equity market and economy for much of the year.

The S&P 500 has risen 1.4 percent since politicians in Washington ended a stalemate Oct. 16 to avoid a debt default and end a partial government shutdown, but the damage to the economy has led investors to expect the Fed to delay scaling back its stimulus for several months.

Corporate earnings continue to pour in, with 47 S&P 500 components expected to report Thursday, including Microsoft Corp and Amazon.com Inc after the close.

"The earnings picture was not supposed to be that great this quarter and in fact we are seeing that. The thing that is disappointing is top-line revenue and those are not good signs," said Keith Bliss, senior vice-president at Cuttone & Co in New York.

"So what is going to drive the market from that point is going to be Washington policy and Fed policy."

S&P 500 futures rose 3.2 points and were above fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures gained 46 points and Nasdaq 100 futures added 2.5 points.

U.S. stocks fell on Wednesday as shares of heavy-equipment maker Caterpillar and semiconductor companies tumbled after earnings, ending the S&P 500's four-session streak of record high finishes.

Dow component 3M Co reported a 6 percent rise in quarterly profit with higher sales across all its businesses. Its shares edged up 0.2 percent to $123.39 before the opening bell.

Ford Motor Co rose 3.2 percent to $18.07 in premarket trade after the second-largest U.S. automaker boosted its full-year global earnings and margin outlook, helped by an improved forecast in Europe and better-than-expected results in the third quarter.

According to Thomson Reuters data through Wednesday morning, of the 160 companies in the S&P 500 that have reported earnings, 66.3 percent have topped Wall Street expectations, above the 63 percent beat rate since 1994 and roughly in line with the 66 percent rate over the past four quarters.

On a revenue basis, 53.8 percent of reporting companies have beaten analysts' expectations, below the 61 percent beat rate since 2002 but above the 49 percent rate for the past four quarters.