DOVER, Del. – The DuPont Co. said Tuesday that its net income more than doubled in the first quarter on a gain from the sale of its performance coatings unit and strong continuing results in its agricultural unit.

CEO Ellen Jamison Kullman said DuPont’s efforts to boost long-term growth are working, despite continued tough economic conditions in Europe and some other markets, pointing to strong demand for the company’s agriculture products both in the U.S. and overseas.

“Growth fundamentals and agriculture markets remain solid, and we expect our product lines to perform very well,” Kullman told analysts on a conference call.

As a result, the company expects full-year sales growth in the “low teens” at the agriculture business, she said. Sales rose 14 percent in that business in the first quarter.

Kullman said the company, expects overall market conditions to stabilize around the middle of this year.

DuPont, which operates a plant in the Town of Tonawanda, reported net income of $3.35 billion, or $3.58 per share, for the quarter ended March 31. That’s up from $1.49 billion, or $1.58 per share, a year ago.