Retlan Manufacturing is one of the largest employers in the Northern Ireland and its principal business is the manufacturing and sale of trailers. The company and its subsidiaries have expanded significantly in the past decade. Much of the expansion in employment has come in the past five years. Since the purchase of SDC Trailers in 1998 from Powerscreen, the company has grown dramatically and is now the largest trailer manufacturer in the United Kingdom.

Retlan was originally a major supplier to SDC which began making trailers in Toomebridge in 1978. The group has factories, with the latest technology, in Toomebridge, Magherafelt, Antrim and Mansfield in England. It also has distribution centres throughout the UK.