Ixia said Tuesday that it has appointed Atul Bhatnagar as the company’s president and chief operating officer. Bhatnagar will also join the company’s board of directors in the third quarter of 2007, the Calabasas-based information technology company said in a release. Bhatnagar previously served as vice president and general manager of Nortel’s Enterprise Data Networks division. Shares in Ixia were up 40 cents, or 4.4 percent, to $9.50 in afternoon trading Tuesday.