May 10 (Reuters) - Britain's competition regulator said on Friday it has initiated a probe into U.S. medical equipment maker Thermo Fisher Scientific's $3.1 billion deal to buy Swedish biotech firm Olink Holding AB.

The Competition and Markets Authority (CMA) has set a deadline of July 8 for its phase 1 decision.

(Reporting by Eva Mathews in Bengaluru; Editing by Shinjini Ganguli)