US STOCKS-Wall St to open higher after ECB announcement, data

* ECB cuts rates, to buy asset-backed securities

* ADP payrolls short of estimates, initial claims up a tad

* Tibco Software (NasdaqGS: TIBX - news) gains before open; to review alternatives

* Ciena stumbles after results, outlook

* Futures up: Dow 37 pts, S&P 6.25 pts, Nasdaq 12.25 pts (Adds ECB decision, data)

By Chuck Mikolajczak

NEW YORK, Sept 4 (Reuters) - U.S. stocks were set to open higher on Thursday, after the European Central Bank cut interest rates to record lows and a flurry of economic data indicated the U.S. economy was steadily improving.

* The ECB cut interest rates to new lows, with its main refinancing rate lowered to 0.05 percent from 0.15 percent, as it attempted to fend off deflation and support a stagnating euro zone economy. ECB President Mario Draghi also said the central bank would begin to purchase asset-backed securities.

* ADP employment data fell a touch short of expectations, as companies hired 204,000 workers in August, against the 220,000 estimate and below 218,000 hired in July. Initial jobless claims rose to 302,000 last week, slightly above the 300,000 forecast but within levels consistent with a strengthening labor market.

* Other data showed the U.S. trade deficit narrowed 0.6 percent in July to its lowest point in six months, pointing to solid economic growth in the third quarter. However, labor costs were far weaker than previously thought in the second quarter, which could provide the Federal Reserve an incentive to maintain its accommodative monetary policy stance for a while.

* Coming up are two reports on the services sector, with the August Markit Services PMI scheduled for release at 9:45 a.m. (1345 GMT) and the Institute for Supply Management's August non-manufacturing PMI at 10:00 a.m. (1400 GMT).

* S&P 500 e-mini futures were up 6.25 points and fair value - a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract - indicated a higher open. Dow Jones industrial average e-mini futures rose 37 points and Nasdaq 100 e-mini futures added 12.25 points.

* Tibco Software rose 7.5 percent to $22.61 in premarket trade after the business software maker said it was reviewing its strategic and financial alternatives as part of a bid to maximize shareholder value.

* Ciena Corp shares dropped 3 percent to $19.85 before the opening bell after the network equipment company posted third-quarter results and provided its fourth-quarter outlook.

* Joy Global (NYSE: JOY - news) slipped 1.4 percent to $61.35 in premarket trade after the mining equipment maker posted lower-than-expected quarterly revenue and profit and narrowed its full-year earnings forecast range. (Editing by Bernadette Baum)