Nordion has sold its last remaining business unit outside of its core business in Ottawa.

The buyer is Best Medical bought another unit of Nordion, Ottawa-based Theratronics, four years ago. Nordion sold its Belgium outfit which has 55 employees.  Nordion officials say the Belgium operation has been losing money for some time.

Both the Belgium branch and Ottawa facility handle medical isotopes and irradiation products. Nordion did not reveal the selling price but did say it will leave $18 million in the Belgian company.

Best has been able to turn around Theratronics by moving into some new areas of technology.