WASHINGTON (AP) -- Chief executives for the largest U.S. companies are more optimistic about sales over the next six months and plan to add more workers.

The Business Roundtable says its April-June quarterly survey found 32 percent of its members expect to expand payrolls in the next six months. That's up from 29 percent in the January-March survey. And 78 percent expect their sales to increase. That's up from 72 percent from the previous survey.

Consumers have kept spending this year, despite an increase in Social Security taxes. That's helped the economy grow at a modest pace.

Still, most of the CEOs don't expect growth to accelerate. They forecast growth of 2.2 percent this year, about the same as first quarter survey.

The group represents leaders of the 200 biggest U.S. companies.