Quest Diagnostics Inc. agreed to buy privately held cardiovascular disease management company Cleveland HeartLab Inc. from equity investors, including Cleveland Clinic.

The companies did not disclose financial terms of the deal.

Cleveland HeartLab was formed in 2009 after being spun off from nonprofit multispecialty hospital Cleveland Clinic.

The deal is expected to be completed in the fourth quarter of 2017, subject to customary regulatory reviews.

Quest plans to set up a national center of excellence in diagnostic information services at Cleveland HeartLab's specialized laboratory in Cleveland, Ohio.

Cleveland Clinic and Quest also formed a collaboration, under which Quest would develop test services for biomarkers on inflammation and other areas of heart disease discovered by Cleveland Clinic.