Complex sentence: By the end of the 1960s Little Chef had become part of Gardner Merchant, itself a subsidiary of Trust Houses, which merged with Charles Forte's hotel and catering empire in 1970 to become Trust House Forte.
Split into simpler sentences: By the end of the 1960s Little Chef had become part of Gardner Merchant, a subsidiary of Trust Houses. In 1970 Trust Houses merged with Charles Forte's hotel and catering empire to become Trust House Forte.