JDA Software Group Inc., which makes inventory management software for retailers, said Thursday it has agreed to buy rival i2 Technologies Inc. for about $434 million. JDA Software said Thursday the deal for the i2 Technologies will help it expand its business. I2 Technologies makes supply chain management software used by manufacturers as they deal with customers and suppliers. It also offers consulting and other services. Under terms of the signed deal, JDA said it would pay a combination of cash and stock valued at $18 a share for i2 Technologies, which is based in Dallas. That is a 9 percent premium over i2's closing price in Wednesday. JDA, based in Scottsdale, Ariz., said the combined company will have a strong financial position, and the acquisition will lead to net annual cost savings of about $20 million.