The pace of U.S. private sector job growth slowed in August for the second month in a row with employers adding 91,000 positions, a report by a payrolls processor showed on Wednesday.

Economists surveyed by Reuters had forecast the report would show a gain of 100,000 jobs. July's private payrolls were revised down to an increase of 109,000 from the previously reported 114,000.

The report is jointly developed with Macroeconomic Advisers LLC.

The ADP figures come ahead of the government's much more comprehensive labor market report on Friday, which includes both public and private sector employment and is forecast to show the economy added 75,000 jobs in August.

(Reporting by Leah Schnurr; Editing by Padraic Cassidy)