(Reuters) - Stock index futures edged higher on Thursday after China surprised the market with another interest rate cut, but gains were kept in check as investors awaited a rate decision by the European Central Bank.

* Futures, which were trading flat, turned higher on news that China was cutting its benchmark deposit rate by 25 basis points and its lending rate by 31 basis points.

* The Bank of England announced that it would keep its bank rate steady at 0.5 percent and expand its quantitative easing program by 50 billion pounds, as expected.

* The European Central Bank is widely expected to cut borrowing costs to a record low to support a deteriorating euro zone economy and complement measures agreed by government leaders last week to tackle the bloc's debt crisis. The rate decision is due at 7:45 a.m. ET (1145 GMT) followed by a news conference at 8:30 a.m. ET (1230 GMT)

* S&P 500 futures were up 3.5 points and were slightly higher than 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 were up 18 points, and Nasdaq 100 futures rose 4.5 points.

* The ADP private-sector employment report for June is due for release at 8:15 a.m. ET (1215 GMT), and is expected to show that 105,000 jobs were created in June versus 133,000 new jobs in May.

* The Labor Dept. releases first-time claims for jobless benefits for the week ended June 30 at