* Initial jobless claims climb more than expected
* Factory orders data due
* AbbVie to buy Pharmacyclics for about $21 bln
* Costco climbs after results
* Indexes up: Dow 0.07 pct, S&P 0.03 pct, Nasdaq 0.15 pct (Updates to market open)
By Chuck Mikolajczak
NEW YORK, March 5 (Reuters) - U.S. stocks were little changed on Thursday, in the wake of two days of declines on the S&P 500, as gains were curbed by a higher-than-expected initial jobless claims report ahead of a report on factory orders.
Initial jobless claims rose to 320,000 in the latest week, above the 295,000 estimate and 313,000 in the prior week. The disappointing claims numbers come after a weaker-than-expected private payrolls report on Wednesday and ahead of Friday's monthly employment report.
"That's a bit of an uptick because we've been pretty consistently in the upper 200,000 range," said Peter Jankovskis, co-chief investment officer at OakBrook Investments LLC in Lisle, Illinois.
"Some movement up or down would be expected, but 320,000 is probably a bit more than people were looking for."
The benchmark S&P index has slowed after a 5-percent surge in February and a record on March 2 with its worst two-day performance since late January. The index was down during four of the past six sessions as investors attempted to gauge the timing of an interest rate hike by the U.S. Federal Reserve.
January factory orders data is scheduled for release at 10:00 a.m. (1500 GMT). Expectations call for orders to rise 0.2 percent versus a 3.4 percent decline in December.
The Dow Jones industrial average rose 12.36 points, or 0.07 percent, to 18,109.26, the S&P 500 gained 0.54 points, or 0.03 percent, to 2,099.07 and the Nasdaq Composite added 7.36 points, or 0.15 percent, to 4,974.50.
AbbVie is to buy Pharmacyclics for about $21 billion, giving it access to what is expected to be one of the world's top-selling cancer drugs and expanding its reach in the profitable oncology field. Pharmacyclics shares jumped 10.4 percent to $254.38 while AbbVie lost 4.6 percent to $57.50.
Costco Wholesale rose 2.4 percent to $150.72 after it reported a better-than-expected quarterly profit. Retailers will be watched as they post monthly sales results for signs of whether lower gas prices have translated to improved spending elsewhere in the economy.
Kroger gained 6.1 percent to $73.88 as the best performer on the S&P 500 after the biggest U.S. supermarket operator reported a 23 percent rise in quarterly profit and forecast full-year earnings above expectations.
The European Central Bank said it will start its new government bond-buying program of 60 billion euros a month on March 9 and raised its economic growth forecast for 2015. It boosted its 2016 inflation forecast to 1.5 percent.
Declining issues outnumbered advancing ones on the NYSE by 1,416 to 1,175, for a 1.21-to-1 ratio; on the Nasdaq, 1,140 issues fell and 976 advanced for a 1.17-to-1 ratio.
The benchmark S&P 500 index was posting 13 new 52-week highs and 2 new lows; the Nasdaq Composite was recording 33 new highs and 10 new lows.
Editing by Bernadette Baum