Chemical maker DuPont will spend less on capital projects next year than initially planned due to uncertainty about the U.S. "fiscal cliff," Chief Executive Ellen Kullman said in an interview.

The company, which has the largest market value among U.S. chemical makers, plans to keep capital spending at around $1.8 billion in 2013 and is delaying some projects until it is clear what U.S. tax policy will be, Kullman said.

The total is about the same as DuPont's capital spending in 2012, even though the company had planned to hike spending in the new year.

"We're not going to spend as much as we thought next year," she said in an interview with Reuters on Wednesday after meeting with DuPont's board of directors.

"We've looked at every program and asked, 'Can we spend less money now and delay some programs six months?'"

Agriculture and nutrition projects may get more funding due to their growth potential, but there's some uncertainty in the automotive sector, where DuPont sells paints and plastics, she said.

"Consumers will hold back until the fiscal cliff is resolved," said Kullman, who has run the Wilmington, Delaware-based company since 2009.

Kullman said she personally is willing to pay higher U.S. federal income taxes to help avert the fiscal cliff, a package of spending cuts and tax hikes due to take effect in January unless Washington lawmakers agree on a budget deal.

Kullman's 2011 compensation package was worth $12.2 million.

"We understand there has to be a balanced equation. There has to be increased revenues and there has to be decreased spending," she said.

If there is only a partial deal, one that doesn't address spending and the U.S. federal debt, Kullman said it could reduce U.S. GDP growth by as much as one percentage point.

"The biggest concern is not that they don't avert the cliff, but that they put forward a plan and never execute, or don't execute in a way that addresses the debt," she said. "Because otherwise you're just going to run up against that debt ceiling constantly."

BUYBACK VS. DIVIDENDS

Late Tuesday, DuPont announced a $1 billion stock buyback and said 2012 profit should hit the high end of its forecast.

DuPont decided a buyback, rather than a one-time dividend, would be better for shareholders, Kullman said. The company pays a 32-cent quarterly dividend currently, with one of the highest yields on Wall Street.

Due to the "fiscal cliff" uncertainty, Wal-Mart , Costco and other U.S. corporations have pulled forward 2013 dividend payouts to 2012, or issued one-time payouts, so shareholders won't have to pay expected higher capital gains taxes in 2013.

DuPont considered that approach, but decided against it, Kullman said.

"With the uncertainty that's out there, and with the tax law changes, we believe it better serves our shareholders to reduce our share count," she said. "Many of our shareholders are tax-exempt funds, so they don't pay tax on dividends."

NATURAL GAS EXPORTS

Kullman said the U.S. should consider the impact exporting shale-derived natural gas would have on the nation's economic growth. Exports are controversial among manufacturing executives in the country.

DuPont uses natural gas in some of its U.S. Gulf Coast plants and other facilities, but does not use nearly as much as rival Dow Chemical Co , which has argued natural gas should stay in the United States.

Asked if DuPont would support exports of natural gas, Kullman said, "I do think as a country we need to first and foremost make sure we have energy security ... If we have great excess reserves that we can monetize, that should be part of a consideration."

(Reporting By Ernest Scheyder; editing by John Wallace and Nick Zieminski)