(Reuters) - DuPont (>> E I Du Pont De Nemours And Co) expects 2012 earnings to come in at the bottom of its prior forecast range, due in part to economic uncertainty circling the globe, the maker of chemicals, hybrid seeds and Kevlar bulletproof fiber said on Tuesday.

The updated forecast, for earnings at the "lower end" of a range of $4.20 to $4.40 per share, came after the company posted a higher-than-expected profit for the second quarter.

Analysts on average expect earnings of $4.25 per share this year, meaning DuPont could fall short of Wall Street's expectations.

Higher taxes and currency conversion should also weigh on results, said Chief Executive Ellen Kullman.

"We're seeing sequential improvement in many markets that have been very sketchy in the first half of the year," Kullman said on a conference call with analysts and investors. "Our ability to forecast is not as great as we used to think it was."

DuPont reported second-quarter net income of $1.18 billion, or $1.25 per share, down from $1.22 billion, or $1.29 per share, a year earlier.

Excluding one-time items, the company earned $1.48 per share. By that measure, analysts expected $1.46, according to Thomson Reuters I/B/E/S.

Revenue rose 8 percent to $11.28 billion. Analysts had expected $11.27 billion.

Sales jumped the most in North America and Latin America, helped largely by strong sales of seeds and other agricultural products. Kullman said she would closely watch North American sales to industrial, commercial and housing customers.

"We need to all be cautious as we look at these markets in the second half of the year," she said.

Europe remains in a recession, Kullman said, echoing previous comments. DuPont is seeing "some strength" in Russia and Turkey's economies, she said.

"The expectations in Europe are very low, and they're kind of bumping along the bottom in a recessionary mode," Kullman said.

PERFORMANCE COATINGS

DuPont's performance coatings business has been for sale since last fall, but so far, the company has declined to publicly acknowledge its discussions with potential buyers.

The performance coatings business primarily sells to Maaco and other auto paint refinishers. Ford Motor Co (>> Ford Motor Company) and General Motors Co (>> General Motors Company) are also key customers.

During the conference call, the first question to Kullman was about the progress of the sale.

"I'm not sure where that question is coming from," Kullman told JPMorgan's Jeff Zekauskas. "If we have anything to announce about any of our businesses or product lines, we will make sure we include you."

Kullman stressed, though, that the performance coatings unit had had a "good performance this year."

TITANIUM DIOXIDE

Sales fell in all of DuPont's businesses during the first quarter, except those connected to the food sector.

In the performance chemicals unit, volume fell 10 percent, primarily because of weak demand for DuPont's titanium dioxide, or Ti02, paint pigment.

A 9 percent jump in selling prices partly offset the drop in volume.

DuPont is the world's largest producer of the critical pigment, which is used to give paint and other coatings a white hue.

Earlier this month Australia-based titanium ore miner Iluka Resources Ltd (>> Iluka Resources Limited) confirmed what many investors have feared for months: Softer demand and higher inventories of the pigment were affecting production.

The news dented shares of Iluka, as well as DuPont's titanium dioxide rivals, Tronox Inc (>> Tronox Incorporated) and Huntsman Corp (>> Huntsman Corporation).

Trying to reassure markets, DuPont (>> E I Du Pont De Nemours And Co) issued its own press release in mid-July, saying Ti02 demand in the second half of the year should be stronger than what Iluka predicted.

On Tuesday DuPont admitted there was "continued softness" in Ti02 demand, particularly in Asia and Europe.

"The market became soft in the second half of 2011, and we have seen slow sequential recovery since then," Kullman said. "We believe that recent comments in the press regarding demand outlook overstated the softness in the market."

DuPont shares were down 1.3 percent at $48.07 on Tuesday morning. At Monday's close, the stock had gained 6.4 percent so far this year.

(Reporting by Ernest Scheyder in New York; Editing by Lisa Von Ahn and Jeffrey Benkoe)

By Ernest Scheyder