WASHINGTON (AP) — Chief executives at the largest U.S. companies are much more optimistic about their sales prospects than they were three months ago, though many remain cautious about hiring.

The Business Roundtable says 72 percent of its members expect sales will increase in the next six months. That's up from 58 percent at the end of last year. And 38 percent plan to invest more in plant and equipment, up from 30 percent in December, when the Roundtable released its last report.

Still, the better outlook hasn't made the group more optimistic about hiring. Twenty-nine percent of CEOs plan to increase hiring over the next six months, the same percentage as the last two surveys.

The Business Roundtable represents CEOs of the 200 largest U.S. corporations.