TTX Co., Chicago, hired Atalanta/Sosnoff to run $18 million in active domestic large-cap growth equities, said Tony Barton, assistant treasurer. Atalanta replaced Montag & Caldwell, which ran a similar portfolio for the $55 million pension plan, Mr. Barton said. Montag & Caldwell was terminated because of performance and trustees' concern that the manager was "not a good fit," he said. Becker, Burke assisted. Montag & Caldwell officials did not return calls seeking comment by press time.