Two of Britain’s big retail chains plan to merge.

The merger of British Home Stores and Habitat-Mothercare will create a group of stores with annual revenue exceeding $1.45 billion. Sir Terence Conran, the designer who founded Habitat and then bought Mothercare stores, will be chairman and chief executive of the combined group, the firms said. British Home Stores, which has 124 department stores in Britain, was valued at $1.223 billion, and Habitat-Mothercare, with 650 outlets in Britain, the United States and Europe, was valued at $965 million.