A growing number of chief executives at the nation's largest companies are slightly more optimistic about the economy for the next six months.

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In fact, many of them expect a boost in hiring.

Business Roundtable's CEO Economic Outlook index rose to 84.5 for the quarter between October and December. That's up from 79.1 in the previous quarter, from July to September, and above the index's long-term average of 79.2.

Thirty-four percent of the executives surveyed expect their companies will increase hiring in the next six months, up from 32 percent in the previous survey, while 73 percent of respondents expect their company's sales to increase. That's also a two percent increase.

But the CEO's expect the economy will grow at 2.2 percent next year, which is unchanged from the previous two polls.

"Our expectations are consistent with an economy that will continue along the path of steady, modest recovery into the first half of 2014," said Jim McNerney, chairman of Business Roundtable and chief executive of Boeing Co. "Many business executives are concerned about the impact of the federal health care law on their companies' costs. Some are responding by 'hedging' their hiring and their investments in the businesses."

The job market has shown improvement in recent months. The economy added 204,000 jobs in October, suggesting employers shrugged off the 16-day partial government shutdown. Employers also have added an average of 202,000 jobs a month from August through October. That was up from an average of 146,000 from May through June.

Growth has also picked up since the last survey. The economy grew at a 2.8 percent annual pace from July through September, up from a 2.5 percent pace in the April to June quarter.

"These numbers are encouraging, we're seeing an uptick, it's modest, but things are heading in the right direction," said John Engler, president of Business Roundtable.

"While there is good news, not everything came up roses in this survey," Engler said. "When asked about cost pressures, the executives said regulatory costs are still a big concern. So, we just have to see if we can make 2014 a lot better."

Business Roundtable is an association of chief executives at the 200 largest companies in the United States. Any reading above the number 50 suggests expansion.

The Associated Press contributed to this report.