By 1955 five companies produced 90% of the UK's motor vehicle output: BMC, Ford, Rootes, Standard-Triumph and Vauxhall. Of the dozen or so smaller producers Rover and Jaguar were strong niche producers. By 1960 the UK had dropped from being the world's second largest motor vehicle producer into third place. Labour-intensive methods, and wide model ranges hindered opportunities to reduce manufacturing costs – the UK's unit costs were higher than those of their major Japanese, European and American competitors. Although rationalisation of motor vehicle companies had started, full integration did not occur. BMC continued to produce vehicles under the marque names of its incorporated companies, many of which competed with each other. Standard-Triumph's attempts to reduce costs by embracing a modern volume production strategy almost led to their bankruptcy in 1960, the result was that they were purchased by the commercial vehicle manufacturing company Leyland Motors. In 1966, BMC and Jaguar came together, to form British Motor Holdings (BMH). Leyland had achieved some sales success with Leyland-Triumph and in 1967 it acquired Rover. By 1966 the UK had slipped to become the world's fourth largest motor vehicle producer. Following a gradual process which had begun in 1964, Chrysler UK (CUK) had fully acquired Rootes by 1967.