Union Bank of Switzerland (UBS) was a large integrated financial services company located in Switzerland. The bank, which at the time was the second largest bank in Switzerland, merged with Swiss Bank Corporation in 1998, to become UBS to form what was then the largest bank in Europe and the second largest bank in the World.UBS was formed in 1912 through the merger of the Bank in Winterthur and Toggenburger Bank, both founded in the early 1860s.