WASHINGTON (AP) — A majority of America's largest companies are ready to step up hiring this year and more than 90 percent expect sales to improve, a new survey found.

The Business Roundtable said March 30 that 52 percent of its members plan to increase hiring in the next six months. That's the largest proportion for the group since it began surveying its members nine years ago. The trade group represents CEOs from roughly 200 of the nation's largest companies.

More than 60 percent also plan to spend more on long-lasting manufactured goods, such as computers and machinery, according to the survey of 142 executives taken in early March.

The group's members are more optimistic than at any point since the survey began in 2002. Its CEO economic outlook index rose to 113, up from 101 in the previous quarterly survey. The index plummeted to -5, its lowest level, in the January-March quarter of 2009.

“Our CEOs see momentum in the economy over the next six months, with increased demand fueling greater investment and job creation,” said Ivan Seidenberg, chairman of the group and CEO of  Verizon Communications Inc.

Still, the executives expect the overall economy to grow only a modest 2.9 percent this year. That's up from their forecast three months ago of 2.5 percent.

While CEO sentiment is improving, Seidenberg said, “it's not a sunny blue sky … there's still lots to worry about," including higher oil prices and the impact of Japan's earthquake, tsunami and nuclear crisis.

Most of the responses to the group's survey were received before Japan's earthquake struck March 11. The Roundtable's members are still assessing the full impact of the disaster on their operations, Seidenberg said, and will likely provide more detail in earnings reports over the next two months.