In an effort to streamline its upper management structure and trim operating expenses, Endurance Specialty Holdings Ltd. announced changes to its executive team on Tuesday.

The Pembroke, Bermuda-based insurance and reinsurance provider said Joan deLemps will assume the role of chief risk officer effective immediately. Ms. deLemps was formerly Endurance's chief underwriting officer and replaces Nicholas Campbell the former chief risk officer. In her new role, Ms. deLemps will have oversight for corporate underwriting, corporate actuarial, risk management and ceded reinsurance and continue to report to new Endurance Chairman and CEO John Charman.

"As we transform Endurance's global insurance and reinsurance footprints and their specialty product offerings, it is critically important that our enterprise risk management capabilities are at the highest and most responsive levels,” Mr. Charman said in a statement. “To that end I have no doubt that Joan, with her broad market leading experience, management capability and insightful guidance and oversight, will achieve that goal.''

Simultaneously, the company said Catherine A. Kalaydjian has assumed the role of chief operations officer, replacing John O'Connor. Ms. Kalaydjian served as Endurance's chief claims officer since March 2007 and was promoted to chief administrative officer in December 2012, retaining her claims role. In addition to these duties, Ms. Kalaydjian will gain management oversight of information technology, insurance and reinsurance underwriting operations, procurement and program management.

Mr. Charman, who took over Endurance in May, said the company hopes to differentiate itself by lowering operating expense ratios and concentrating on its specialty businesses.

"Endurance is committed to quickly and significantly expanding our global footprint and product capabilities in our insurance and reinsurance specialty businesses,” Mr. Charman said in the statement. “Cathy will be instrumental in helping us realize that goal.”