Blacks Leisure is expected to convert the entire chain to its own formats which include First Sport, Blacks Outdoor and Active Venture.
Millets is part of The Outdoor Group, which was formed three years ago to buy the stores from Sears, the former retail group.
Under Sears the stores were mis-managed and under-invested, and become dated and run-down. However, it retained a loyal following with its range of hiking boots and low-priced outdoor clothing. The Outdoor Group achieved profits of pounds 5m last year from sales of pounds 80m.
Blacks Leisure has been keen to expand to compete with rivals such as JJB Sports, which has expanded by buying the Sports Division chain of stores. Sports Division was largely the old Olympus Sports stores, which also used to be part of the Sears empire.
Sears ceased to exist earlier this year when it was taken over by Philip Green, the retail entrepreneur.
He has since broken the group up, selling off Freemans to Otto Versand and its women's clothing chains to Arcadia.Reuse content