US STOCKS-U.S. stocks flat in choppy trading after mixed economic data

* April construction spending up, consumer spending flat

* Manufacturing picks up in May

* Intel (Swiss: INTC.SW - news) falls on Altera (NasdaqGS: ALTR - news) buy, weighs on Nasdaq, Dow and S&P

* Cancer drug maker's jump after data presentation

* Indexes up: Dow 0.03 pct, S&P 0.02 pct, Nasdaq 0.04 pct (Adds details, comment, updates prices)

By Tanya Agrawal

June 1 (Reuters) - U.S. stocks were flat in choppy trading late on Monday morning, giving up their gains from a strong opening, as investors digested a slew of data that sent a mixed picture on the pace of the economy's recovery.

Data from ISM showed that the pace of manufacturing growth rose in May. Other data showed construction spending surged in April, but consumer spending was unexpectedly flat.

The data left investor's with a mixed view about the strength of the economy's recovery as they try to gauge when the Federal Reserve will ultimately raise interest rates.

Boston Fed President Eric Rosengren said he would like to begin raising rates as soon as possible, but risks from the slowdown in China and Europe in particular loomed large even as growth at home was still not strong enough.

The dollar and the yields on U.S. debt rose after the data.

"We're seeing a lot of counter trends in the market," said Rick Fier, director of trading at Conifer Securities in New (KOSDAQ: 160550.KQ - news) York. "One thing this market hasn't been seeing is inflows which gets put to work."

Fier said the mixed data, rumors about Greece reaching a deal and volatility in currencies and bond yields added to the choppiness.

Greece missed a self-imposed Sunday deadline for reaching an agreement to unlock aid, the same day Economy Minister George Stathakis said he expected a deal in "a few days".

At 11:42 a.m. ET (1542 GMT) the Dow Jones industrial average was up 5.57 points, or 0.03 percent, at 18,016.25, the S&P 500 was up 0.35 points, or 0.02 percent, at 2,107.74 and the Nasdaq Composite was up 1.95 points, or 0.04 percent, at 5,071.98.

Five of the 10 major S&P indexes were lower. The teleservices index was the biggest loser with a 0.62 percent fall.

Intel shares fell 1.8 percent to $33.85 and were the biggest drag on the three major indexes after the company agreed to buy programmable-chip maker Altera for $16.7 billion. Altera rose 6 percent to $51.80.

OM Group (NYSE: OMG - news) jumped 28 percent to $33.95 after Apollo Global Management agreed to buy the magnet and battery maker for $1.03 billion.

Citigroup (NYSE: C - news) was up 1.1 percent at $54.68 on a Wall Street Journal report that the bank is expected to close its troubled Banamex USA unit. Goldman Sachs (NYSE: GS-PB - news) upgraded the stock to "buy" from "neutral".

Immunogen (NasdaqGS: IMGN - news) surged 67 percent, while Oncothyreon jumped 16.6 percent, leading a rise in cancer drug makers' stocks after they presented positive data at a conference.

Advancing issues outnumbered decliners on the NYSE by 1,482 to 1,477, for a 1.00-to-1 ratio on the upside. On the Nasdaq, 1,377 issues fell and 1,255 advanced for a 1.10-to-1 ratio favoring decliners.

The S&P 500 index showed 10 new 52-week highs and six new lows while the Nasdaq recorded 73 new highs and 36 new lows. (Editing by Savio D'Souza)