* Jobless claims, pending home sales data on tap
* PepsiCo to buy Russia's Wimm-Bill-Dann for $5.4 bln
* Futures up: Dow 45 pts, S&P 5.2 pts, Nasdaq 12.5 pts
NEW YORK, Dec 2 (Reuters) - U.S. stock index futures rose slightly on Thursday on expectations the European Central Bank may act to relieve market worries of a spreading euro zone debt crisis.
* The Dow and the S&P 500 scored their biggest gains in three months on Wednesday as efforts to resolve the EU's debt crisis helped push the S&P above 1,200. The benchmark faces strong resistance in the 1,225-1,230 area.
* The European Central Bank faced pressure to take steps to help contain the euro zone's debt problems, but could upset financial markets if it fails to announce new anti-crisis measures.
* Investors also awaited U.S. data on the jobs and housing markets, which may help to confirm the recent signs of strength in the economic recovery.
* S&P 500 futures rose 5.2 points and were slightly 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 45 points, and Nasdaq 100 futures added 12.5 points.
* Treasury Secretary Timothy Geithner, who is leading talks for the White House along with budget director Jack Lew, said Republicans and Democrats held a "civil, constructive discussion," but declined to give specifics. Negotiations are expected to continue Thursday.
* The cost of insuring peripheral euro zone debt against default eased ahead of the ECB meeting, while the euro, which has recently traded in the same direction as U.S. equities, gained ground against the U.S. dollar.
* In company news, PepsiCo Inc agreed to buy Russian juice and dairy producer Wimm-Bill-Dann for $5.4 billion.
* American International Group Inc shares could get attention after Reuters reported the insurer could receive at least three separate bids for its Taiwan unit.
* Costco Wholesale Corp posted a 9 percent rise in November same-store sales, helped by higher gasoline prices and strengthening foreign currencies.
* Economic data on tap includes weekly initial jobless claims, due at 8:30 a.m. EST (1330 GMT), with forecasts at 425,000 from 407,000 last week. Pending home sales for October, expected at 10 a.m. EST (1500 GMT), are seen down 0.5 percent versus a decline of 1.8 percent in the prior month.