NEW YORK, Oct 22 (Reuters) - U.S. stock index futures were flat on Wednesday, implying that buyers were taking a pause following the biggest four-day rally for the S&P 500 since January 2013.
* Major indexes jumped about 2 percent on Tuesday, lifted by strong corporate results, especially in the tech sector, and a Reuters report that the European Central Bank was considering buying corporate bonds.
* The S&P 500 has gained 4.2 percent over the past four sessions, putting it about 3.5 percent from its closing record, and up more than 6 percent from its session low last Wednesday, when the benchmark nearly reached correction territory. It closed Tuesday above both its 14-day moving average and its 200-day average, a sign of improving near-term momentum.
* Earnings continue to be in focus. Late Tuesday, both Yahoo Inc and Broadcom posted better-than-expected revenue growth. Yahoo rose 3.3 percent to $41.52 in premarket trading and was the Nasdaq's most active premarket stock.
* While earnings have largely come in strong so far this quarter, concerns continue to swirl over the pace of global economic growth and the timing of central bank policy changes.
* Investors will be looking ahead to the consumer price index, which is seen as flat in September. The report, due at 8:30 a.m., is the first read on CPI since August's 0.2 percent dip, the first time prices fell in near 1-1/2 years, which was seen as lessening the urgency for the U.S. Federal Reserve to raise interest rates.
Futures snapshot at 6:55:
* S&P 500 e-minis were falling 3.25 points, or 0.17 percent, with 180,299 contracts changing hands.
* Nasdaq 100 e-minis were down 1.75 points, or 0.04 percent, in volume of 23,940 contracts.
* Dow e-minis were down 3 points, or 0.02 percent, with 26,384 contracts changing hands. (Editing by Chizu Nomiyama)