* Futures up: Dow 18 pts, S&P 0.5 pts, Nasdaq 5 pts
By Yashaswini Swamynathan
May 31 (Reuters) - U.S. stock index futures were little changed on Tuesday as investors digested the possibility of an interest rate hike in the coming months and awaited data for clues regarding the strength of the economy.
* Federal Reserve Chair Janet Yellen on Friday pointed at improvement in the economy and a strong labor market, and she said a rate hike in the coming months would likely be appropriate.
* Yellen's comments come after months of uncertainty on the Fed's stance on rates swayed the markets, especially worrying investors after the first quarter started on a weak note.
* Her comments helped Wall Street close higher on Friday, capping off its strongest week since March. The benchmark S&P 500 index has risen about 1.6 percent in May and is set to record its third straight month of gains. U.S. markets were closed on Monday for the Memorial Day holiday.
* Traders raised their expectations of a rate hike in June to 28 percent after Yellen's speech, from just over 4 percent at the start of May, according to CME Group's FedWatch tool.
* St. Louis Fed President James Bullard said on Monday that global markets appear to be "well-prepared" for a summer rate hike, although he did not specify a date for the policy move. The Fed next meets on June 14-15.
* Data due Tuesday is expected to show consumer spending, the Fed's preferred measure of inflation, likely rose 0.2 percent in April, compared with a 0.1 percent increase in March. The Fed's inflation rate target is 2 percent.
* Separately, a report from the Conference Board on consumer confidence is expected to show the index at 96.0 in May, up from a reading of 94.2 in the previous month.
* The data is expected at 8:30 a.m. ET (1230 GMT).
* Celator Pharma jumped 73.2 percent to $30.37 premarket after agreeing to be bought by Jazz Pharma for about $1.5 billion. Jazz Pharma was untraded.
* Utility Westar Energy was up nearly 9 percent at $57.65 after agreeing to be bought by Great Plains for $8.6 billion. Great Plains was untraded premarket.
Futures snapshot at 7:02 a.m. EDT:
* Dow e-minis were up 18 points, or 0.1 percent, with 30,862 contracts changing hands.
* S&P 500 e-minis were up 0.5 points, or 0.02 percent, with 185,067 contracts traded.
* Nasdaq 100 e-minis were up 5 points, or 0.11 percent, on volume of 27,680 contracts. (Reporting by Yashaswini Swamynathan in Bengaluru; Editing by Savio D'Souza)