WASHINGTON (MarketWatch) -- U.S. private-sector firms created 13,000 more jobs in June, according to the ADP employment report released Wednesday. Job growth was "disappointingly weak," said Joel Prakken, chairman of Macroeconomic Advisers, which produces the report from anonymous payroll data supplied by ADP. Private-sector job growth was revised higher in May to 57,000 from 55,000 earlier. Economists are expecting nonfarm payrolls to fall by 130,000 when the government reports its estimates on Friday, including the loss of some 250,000 temporary workers at the Census Bureau. Private-sector employment has increased five months in a row.