* Facebook slumps in premarket after earnings
* Initial jobless claims climb, Chicago PMI on tap
* Futures off: Dow 2 pts, S&P off 0.4 pt, Nasdaq off 9.25 pts
By Chuck Mikolajczak
NEW YORK, Jan 31 (Reuters) - U.S. stocks were poised for a modestly lower open on Thursday as economic data continued to paint a mixed picture of the economy and as investors sifted through a host of corporate earnings reports.
Data showed the number of Americans filing new claims for unemployment benefits increased to 368,000 last week, bouncing off five-year lows in the prior week and exceeding an estimated 350,000, pointing to modest improvement in the labor market.
The claims data comes ahead of Friday's payrolls report, which is expected to show employers added 160,000 jobs in January after an increase of 155,000 in December.
A separate report showed incomes rose by 2.6 percent in December, the most in eight years, in a positive sign that could propel the economy forward.
Facebook Inc shares lost 6.4 percent to $29.23 in premarket trading. The company doubled its mobile advertising revenue in the fourth quarter but that growth trailed some of Wall Street's most aggressive estimates.
The S&P 500 is up 5.3 percent for the month, after legislators in Washington temporarily sidestepped a "fiscal cliff" of automatic tax increases and spending cuts that could have derailed the economic recovery, and amid improving economic data and better-than-expected corporate earnings.
But the benchmark index has stalled recently and is virtually flat for the week, hovering near the 1,500 mark, as investors look for more catalysts to justify further gains.
"Unfortunately it's still a mixed picture, it appears we are just getting a lot of conflicting data right now," said Jack Ablin, chief investment officer at BMO Private Bank in Chicago.
"There is certainly a lot of information coming out this week - a lot of economic data, a lot of earnings and of course we have the employment number looming Friday, so with 1,500 right here, my guess is there is just not enough conviction to push us substantially higher yet."
United Parcel Service Inc lost 1.8 percent to $79.75 in premarket trading after the world's largest parcel delivery reported fourth-quarter earnings below analysts' estimates on Thursday and forecast weaker-than-expected profit for 2013.
S&P 500 futures fell 0.4 point and were slightly below 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 dipped 2 points, and Nasdaq 100 futures lost 9.25 points.
Later in the session at 9:45 a.m. (1445 GMT), the Institute for Supply Management Chicago releases January index of manufacturing activity. Economists in a Reuters survey forecast a reading of 50.5 compared with 50.0 in December.
Qualcomm Inc gained 6.5 percent to $67.66 in premarket trading after the world's leading supplier of chips for cellphones beat analysts' expectations for quarterly profit and revenue and raised its financial targets for 2013.
Thomson Reuters data through Wednesday morning shows that of the 192 companies in the S&P 500 that have reported earnings this season, 68.8 percent have exceeded expectations, a higher proportion than over the past four quarters and above the average since 1994.
Overall, S&P 500 fourth-quarter earnings are forecast to have risen 3.8 percent. That's above the 1.9 percent forecast from the start of the earnings season, but well below a 9.9 percent fourth-quarter earnings growth forecast on Oct. 1, the data showed.
WMS Industries Inc surged 55.7 percent to $25.48 in premarket after the company agreed to be acquired by Scientific Games Corp for $26 per share in cash. Scientific Games advanced 15.9 percent to $10.35.