Wall Street's main indexes were on track for strong weekly gains on Friday after data showed the U.S. economy unexpectedly shed jobs last month, tempering speculation of the Federal Reserve raising borrowing costs in September. A Labor Department report showed nonfarm payrolls fell 23,000 in July, far below the 80,000 job additions that economists polled by Reuters had expected. "For the Fed, the report could keep policymakers on track to hike (rates); however, there may be somewhat less urgency, in our view, with the timing likely dependent on incoming inflation and employment data over the months ahead," said Brian Therien, senior analyst at Edward Jones. Money market data showed traders pared back expectations for an increase in borrowing costs in September, with odds of a hike now at about 20 percent, from 55 percent before the report, according to data compiled by LSEG. Under new Chair Kevin Warsh, the U.S. central bank has offered investors little forward guidance on monetary policy, sharpening the focus on economic data and commentary from policymakers. Payrolls, however, have a te