More than half of the chief executives of large U.S. companies said they expect to spend and hire more over the next six months despite slower economic growth.

The Business Roundtable said Tuesday that 51 percent of CEOs polled expect to increase hiring. Last quarter's level of 52 percent had been the highest since the trade group began surveying its members in 2002.

The survey began in mid-May and ended on June 3, the day the government released a May jobs report, which showed a steep pullback in hiring by employers. The unemployment rate rose to 9.1 percent.

The survey drew responses from 135 CEOs.

Business Roundtable represents CEOs from the nation's 200 largest companies, which have had "pretty steady" hiring plans in recent months, said the group's chairman, Ivan Seidenberg, who is also the CEO of Verizon Communications Inc.

Small businesses, on the other hand, have had a harder time accessing credit and have been much slower to add back jobs lost during the recession.

A national survey of small business owners, also released Tuesday, showed declining optimism among owners of small businesses, the third straight monthly drop. According to the survey of 733 businesses by the National Federation of Independent Businesses, small businesses have added almost no jobs in the past three months as sales remain weak and costs rise.

On the other hand, most CEOs of the country's biggest companies seem confident about their own company's prospects -- 87 percent forecast higher sales, compared to 92 percent last quarter.

More than 60 percent also plan to buy more goods for their companies such as computers, software and machinery, a sign of confidence in future growth.

But Business Roundtable said the CEOs in nits survey expect the economy to grow a modest 2.8 percent in 2011, down from an earlier forecast of 2.9 percent.

Economists surveyed by The Associated Press in April expected even weaker economic growth this year of 2.3 percent.

While the CEOs responding to the Business Roundtable survey appear optimistic, consumers are stressed by high energy costs and overall weak hiring.

Oil and gas prices have come down from recent highs because of concerns that the global economy is weakening and will require less fuel. But energy costs remain high and are still a "kitchen table" issue for consumers, retarding spending on goods and services, Seidenberg said. Consumer spending makes up 70 percent of U.S. economic activity.

A government report on wholesale prices out Tuesday showed that wholesale gas prices rose by the smallest amount in eight months. Economists hope that the U.S. economy can grow faster in the second half of the year if gasoline prices decline, leaving shoppers with more money to spend on other goods.