WASHINGTON (AP) — Only about one-third of chief executives of the largest U.S. companies expect to hire or spend more in the next six months, down sharply from about half who said so three months ago.

The Business Roundtable says rising oil prices earlier this year, fears surrounding Europe's debt crisis and political wrangling over the U.S. borrowing limit have made the business and economic environment more uncertain.

CEOs are also more pessimistic about the economy: They are forecasting 1.8 percent growth this year, down from a 2.8 percent estimate in last quarter's survey.

The results are based on a survey of 140 CEOs of large companies from Aug. 29 through Sept. 16.