* April consumer spending biggest increase in four months
* CardConnect jumps - First Data to buy company for $750 mln
* Dow down 0.13 pct, S&P off 0.13 pct, Nasdaq up 0.04 pct (Updates to open)
May 30 (Reuters) - U.S. stocks opened slightly lower on Tuesday after a three-day holiday weekend as oil prices fell and investors parsed a barrage of economic data for a reading on the health of the economy.
While stocks are trading at record levels, helped by strong first-quarter corporate earnings, investors are keeping a close eye on data as well as political developments in Washington.
U.S. consumer spending recorded its biggest increase in four months in April and monthly inflation rebounded, pointing to firming domestic demand that could allow the Federal Reserve to raise interest rates next month.
The core PCE price index - the Fed's preferred inflation measure - increased 1.5 percent in the 12 months through April. The central bank has a 2 percent target.
The U.S. Conference Board is likely to report that its consumer confidence index was little changed in May.
"We are expecting confidence to slip as the political turmoil in Washington weighs. Nonetheless, the confidence index is expected to stay within its upper range," Peter Cardillo, chief market economist at First Standard Financial, wrote in a note. "We look for a mixed session as the macro news is digested."
At 9:36 a.m. ET (1336 GMT), the Dow Jones Industrial Average was down 26.65 points, or 0.13 percent, at 21,053.63, the S&P 500 was down 3.27 points, or 0.13 percent, at 2,412.55.
The Nasdaq Composite was up 2.33 points, or 0.04 percent, at 6,212.53.
Nine of the 11 major S&P 500 sectors were lower, with the energy index's 0.82 percent fall leading the decliners.
Oil prices were lower, pressured by concerns that production cuts by the world's big exporters may not be enough to drain a global glut that has depressed the market for almost three years.
CardConnect's shares jumped 11 percent to $15.06 after First Data agreed to buy the payment processor for $750 million. First Data slipped 0.1 percent.
Protagonist Therapeutics soared as much as 81 percent to $14.85 after the drug developer signed a collaboration with Johnson & Johnson to develop a drug for inflammatory bowel disease. Johnson & Johnson fell 0.4 percent.
Atwood Oceanics was up 21.2 percent at $9.78 after offshore driller Ensco said it would buy its smaller rival in a deal valued at about $839 million. Ensco was down 6.5 percent at $6.25.
Declining issues outnumbered advancers on the NYSE by 1,658 to 888. On the Nasdaq, 1,323 issues fell and 917 advanced.
The S&P 500 index showed 28 new 52-week highs and 11 new lows, while the Nasdaq recorded 82 new highs and 70 new lows. (Reporting by Tanya Agrawal; Editing by Saumyadeb Chakrabarty)