Roche Diagnostics named a new CEO for its North American operations today, according to an e-mail distributed to company employees.

Phillips

The Indianapolis headquarters will now be led by Jack Phillips, currently head of commercial operations for North America and Japan at Ventana Medical Systems, which makes devices and chemicals used in tissue diagnostics. Ventana, based in Tucson, Ariz., was acquired by Roche in 2008.

Phillips will replace Michael Tillmann, who resigned on Friday after 18 months as chief of the North American diagnostic operations.

Roche officials gave no reason on Monday for Tillmann’s departure from the position, and did not say what his current status is with Roche. The company’s worldwide headquarters are in Basel, Switzerland.

Roche is one of the area’s 15 largest employers, sustaining 2,900 well-paying jobs at campuses in Indianapolis and Fishers. But it has cut jobs recently in its flagging insulin-pump business and is in the midst of moving 300 jobs connected to its lab-equipment business to Germany.

As IBJ reported last month, Roche has steadily lost market share in the diabetes market, which accounts for the biggest chunk of activity on the Indianapolis campus.

Those and other concerns had company insiders speculating that big changes would come once Daniel O’Day, a 22-year Roche veteran, became chief of the global diagnostics business Jan. 1. Replacing Tillmann with Phillips is one of his first moves.

The company also announced today that Kent Kost, president of the Roche Diagnostics operations division, will take the position of global head of quality and regulatory for diagnostics, based in Indianapolis. Kost succeeds Frank Pitzer in his new role. Kost will continue to hold his old job until a successor is found.