U.S. chief executive officers sounded a more confident note on the economy, with more planning to add jobs than cut them over the next six months, a survey released on Wednesday found.

Twenty-nine percent of U.S. CEOs told the Business Roundtable they planned to add jobs in the United States over the next six months, more than the 21 percent who planned to cut. That marked the first time since the first quarter of 2008 that more planned to add jobs than cut them -- a crucial change for an economy recovering from its worst recession in decades.

The majority of CEOs -- 73 percent -- expect their companies' sales to increase over the next six months, and a plurality, 47 percent, plan to boost U.S. capital spending over that time.

CEOs look for a 2.3 percent rise in real U.S. GDP in 2010, the survey found. The overall U.S. CEO Economic Outlook Index stood at 88.9, up from 71.5 at the end of 2009 and the highest since the second quarter of 2006.

Business Roundtable member companies, who were surveyed between March 15 and 30, generate nearly $6 trillion in collective revenue and employ more than 12 million people.

(Reporting by Scott Malone; Editing by Lisa Von Ahn)