Magellan Health Services Inc. of Avon reports that it is losing contracts with a large customer in its specialty pharmacy segment — a customer that provided $60.4 million in revenue to the insurer last year.

Magellan did not identify the company, which has decided not to renew its contracts with the insurer. The contracts brought in $28.5 million during the first six months of this year, according to a company filing Monday with the U.S. Securities and Exchange Commission.

The company would not explain why and when it reports nonrenewed contracts with federal regulators.

Matthew Sturdevant