SAO PAULO, Sept 26 (Reuters) - Brazil will likely expand area planted with cotton by some 23 percent this season due to better prices, a favorable exchange rate and a new genetically modified seed, the president of the national growers' association said.

Farmers plan to sow 1.076 million hectares (2.7 million acres) for a crop and produce 1.5 million tonnes in the 2013/14 season starting now, President of the Abrapa association Gilson Pinesso said in the Thomson Reuter's Trading Brazil chat room late Wednesday.

A year earlier, farmers in the world's No. 4 cotton producer largely favored corn and other crops because of lower prices for the textile.

"There was an improvement in internal cotton prices and also the launch of a new technology, BT II, in Brazil," Pinesso said. "This will help producers obtain a higher productivity and combat bugs that attack the crops."

With a weaker Brazilian currency favoring exports, farmers have already sold about 30 percent of the expected cotton crop in forward sales, he said.