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NEW YORK, Jan 5 (Reuters) - U.S. private employers added 297,000 jobs in December, the biggest increase since at least 2001, compared with a revised gain of 92,000 in November, a private report showed on Wednesday.
The median estimate from 27 economists surveyed by Reuters for the ADP Employer Services report was for a rise of 100,000 private-sector jobs in December.
The November figure was originally reported as a gain of 93,000.
U.S. stock index futures pared losses after the data, while U.S. Treasury prices fell, and the dollar extended gains against the yen and euro.
"We've been building towards a big number ... That's pointing to a big payroll number ahead, and I think we'll get a big healthy report on Friday," said Andrew Wilkinson, senior market analyst at Interactive Brokers Group in Greenwich, Connecticut.
The ADP figures came ahead of the government's much more comprehensive labor market report coming on Friday, which will include both public and private sector employment.
That report is expected to show a rise in overall nonfarm payrolls of 140,000 in December, based on a Reuters poll of analysts, but a rise in private payrolls of 145,000. [ECI/US]
Economists often use the ADP report to fine-tune their forecasts for the payrolls numbers, though it is not always accurate in predicting the outcome.
The ADP report is jointly developed with Macroeconomic Advisers LLC. (Reporting by Caroline Valetkevitch, additional reporting by Ryan Vlastelica; editing by Jeffrey Benkoe)