The OU was the first UK university to offer its own fundraising credit card when it joined forces with Beneficial Bank nine years ago.
Since then the use of OU affinity cards and loans has raised around pounds 1.4million for the university.
The merger will not affect this relationship between Beneficial and the OU, but new Open University personal loans will be offered under the new brand name, Hamilton Loans Direct, and one immediate benefit of the merger is that interest rates will be lower. Existing Beneficial Direct loans will not be affected.
The Open University Visa card rates remain unchanged.
The changes follow a merger of the US parent companies. The combined UK group is now the country's largest dedicated consumer finance business with more than 3.1million customers in all, and is one of the UK's top ten issuers of credit cards.
About 2.1million cards are currently in issue through more than a hundred affinity partner organisations. It also has 187 branches throughout the UK, and is a leading provider of retail finance.
In addition to Goldfish and the GM credit card for Vauxhall, the group provides Visa cards and consumer finance for a huge number of major household names. These include Saga, UNICEF, BSkyB television, English Heritage, Scottish Power, United Airlines, Dixons, Halfords, Boots the chemist and Sainsbury's Homebase.
OU affinity marketing manager Liz Allison welcomed the merger:
"For Open University Visa card holders this means a larger, financially stronger, organisation behind our Visa cards.
"It also strengthens the established partnership between the OU and the UK's premier provider of affinity financial services and fund-raising credit cards."
Anyone wishing to apply for an OU Visa card should call 0800 161 162; or for loans contact 0800 716 796.
The customer service number for existing OU Visa cards holders remains unchanged: 0345 660660.
There is also an Open University Gold Card, specially designed for MBA students and graduates who meet the Bank's acceptance criteria.
Further details are available from Customer Services on 0345 880880.