TORONTO - Sun Life Financial Inc. has signed a deal to buy U.S. company Pinnacle Care International Inc. for $108 million.

Pinnacle Care helps people access an initial or second medical opinion to make treatment decisions for complicated diagnoses.

The company is based in Maryland and has more than 170 employees.

Sun Life says PinnacleCare will become part of its U.S. stop-loss and health business.

The insurer says PinnacleCare's services are currently available to more than two million people and it will look to grow that through its distribution network and employer relationships.

The deal is expected to close later this year, subject to customary closing conditions and regulatory approval.