INDIANAPOLIS – Dow AgroSciences is planning a $340 million expansion of its research operations in Indianapolis and potentially add more than 550 workers in the coming years.

The company announced Thursday it expected to open a new 14,000-square-foot greenhouse this year, followed by a 175,000-square-foot research facility in early 2012.

The subsidiary of Midland, Mich.-based Dow Chemical Co. produces agricultural products such as seeds and pesticides. It has moved heavily in recent years into biotechnology research to develop new products.

Dow AgroSciences currently has about 1,200 workers at its Indianapolis headquarters.

Gov. Mitch Daniels said the expansion "makes Indiana a true world capital of agricultural science."