Ann Street Group - which owns Conquest Inns and Lionheart Inns - has merged with C.I. Traders and Le Riche Group.
The move will see the Jersey-based brewer and pub operator form part of a wider group with pubs, hotels and restaurants as well as interests in the off-trade, the manufacture of food products and soft drinks, clothes retailing and consumer finance.
It should see the company grow to be a major force on the Channel Islands according to an industry spokesman.
"Bringing the three groups together will mean that Ann Street is now one of the biggest companies in the Channel Islands, perhaps even the largest of its kind," he said.
"It will now have a much bigger influence not just in the Channel Islands but also on the UK mainland and France, where it also has interests."
As well as its 61 tenanted pubs and 16 managed houses, the group operates Blubeckers and Edwinns restaurants. It is currently in negotiations to sell its 16-strong Lionheart chain for a cash consideration.
The merger will bring together three companies with a wide range of retailing and leisure activities including:
- wholesaling and retailing of groceries, alcoholic and non-alcoholic beverages and household goods
- operation of pubs, hotels and restaurants
- manufacture of soft drinks and other food products and brewing
- operation of the Marks and Spencer franchise in Jersey
- the provision of consumer finance.