By Kate Gibson, MarketWatch

NEW YORK (MarketWatch) -- U.S. stocks tallied mild gains Thursday after better-than-expected data on the housing front added to cheer that came with an upbeat forecast from Citrix Systems Inc.

After a tepid start, stock indexes picked up a bit of steam after the National Association of Realtors reported its index of pending home sales climbed 4.1% in March to a two-year high.

Results from PulteGroup Inc. (PHM) also boosted housing-related shares, with the builder reporting less of a quarterly loss than Wall Street expected, its losses narrowing on improving home-sale prices.

Of the 51% of the S&P 500 companies that have reported first-quarter results so far, 72.4% have reported earnings above expectations; 11.8% reported earnings in line with expectations and 15.7% reported earnings below estimates, according to Thomson Reuters analyst Greg Harrison.

Since 1994, a typical quarter would have 62% of companies beating estimates; 18% matching and 20% missing. Over the past four quarters, 68% beat estimates; 10% matched and 22% missed, Harrison added.

The Dow Jones Industrial Average (DJI) rose 40.03 points, or 0.3%, to 13,130.75.

The S&P 500 Index (SPX) climbed a fraction to 1,391.10, with telecommunications and consumer discretionary the leading sectors among its 10 major industry groups.

Leading gains on the S&P, Citrix Systems (CTXS) rose 10% after the software maker projected 2012 earnings that beat estimates.

The Nasdaq Composite (RIXF) rose 2.75 points, or 0.1%, to 3,032.37.

Advancers pulled just ahead of decliners on the New York Stock Exchange, where 210 million shares traded by 11:05 a.m. Eastern.

Weighing on sentiment, weekly jobless claims came in virtually unchanged.