Custom Fleet will be combined with GE's existing fleet services businesses in the UK, Australia and New Zealand.
In the UK, this will mean GE's fleet operations will increase to a fleet of almost 70,000 units. Globally, Custom Fleet's 130,000 vehicles will bring GE's worldwide total to 1.33 million.
Custom Fleet operates fleet leasing and management companies in Australia, New Zealand and the United Kingdom, as well as one of Australia's fuel management cards, Fleet Card.
Rich Green, managing director of GE Fleet Services UK, said: "Adding 130,000 vehicles to our global fleet operation provides further scale, operating synergies and expertise to our business. At a UK level, the acquisition of Custom Fleet is a perfect strategic fit and will expand our product and service portfolio in a highly complementary manner.
'The success of our business is built upon people, service, customer focus and an extensive product set. This acquisition not only expands our portfolio and channels to market, it also accelerates our growth and allows us to inherit a successful business, a complementary service portfolio and a new set of product and market innovations to broaden our reach."