Also

* United Online Inc. hired former Advertising.com executive Jeremy Helfand to lead the Internet company’s sales efforts. The Woodland Hills company said Helfand would oversee the unit that sells advertising for its NetZero, Juno, BlueLight and Classmates services.

* Primedex Health Systems Inc. of Los Angeles said it would buy Radiologix Inc. of Dallas for $82.5 million in cash and stock to become the largest U.S. operator of diagnostic imaging centers.

* Wal-Mart Stores Inc. repeatedly failed to accurately tag or price items in stores in Arizona, according to a complaint by Atty. Gen. Terry Goddard. A spokesman for Wal-Mart said it was working with the state “to resolve this issue.”

* Calpine Corp. of San Jose, operating under bankruptcy protection, agreed to sell a Massachusetts power plant to a unit of BG Group for $90.2 million.