Dow Chemical posted a better-than-expected 33% jump in quarterly profit as farmers in the Americas bought more of its seeds and pesticides, overshadowing a decline in European demand for its plastics.

Dow, the largest U.S. chemical maker by sales, forecast that demand for its seeds and crop-protection products would drive further growth after a quarter in which its agricultural science business posted the highest sales growth of its various units.

Sales at Dow's agriculture science business, which supplies seeds, oils and farm chemicals, rose 14% to $2.1 billion in the first quarter, the company said in a statement.

"Two-thirds of the increase in revenues and profit came from new (agricultural science) products. That will continue to set records for us this year, and the next several years," Chief Executive Andrew Liveris told Reuters by telephone.

Rivals DuPont and Monsanto have also reported higher quarterly results due to demand for drought-hardy seeds and crop chemicals from farmers looking to boost yields ahead of the spring planting season.

The company's net income rose 33% to $550 million, or 46 cents per share, in the first quarter from $412 million, or 35 cents per share, a year earlier.

Excluding one-time items, the earnings were 69 cents per share, well ahead of the 61 cents analysts had estimated.

Revenue, however, fell 2% to $14.40 billion, missing the average analyst estimate of $14.88 billion, according to Thomson Reuters I/B/E/S.

Sales at Dow's performance plastics unit, still the company's biggest, fell 3% to $3.5 billion due to weak demand in Europe.