Volvo made its entry into the tractor market by partnering with Swedish manufacturer Bolinder-Munktell in 1943. The tractors produced by both companies shared many similarities, and in 1950, Volvo acquired Bolinder-Munktell. They maintained their separate brands until 1957, when all tractors began to be marketed under the unified Bolinder-Munktell-Volvo brand. This branding was revamped in 1973 to Volvo BM, reflecting the stronger recognition of the Volvo name. In 1978, the company formed a joint venture with Valmet, and in 1985, Volvo sold its entire tractor division to Valmet, which is now known as Valtra.