Commercial bank HSBC and US investment bank Merrill Lynch are pumping $1bn (£630m) into a new global Internet financial services brand.
The new bank, which has yet to be named, will launch in the UK later this year, before being rolled out to Australia, Canada, Germany, Hong Kong and Japan.
The partners will have an equal stake in an online bank offering accounts, unit trusts and stock-broking services.
Customers will have access to the Link cash machine network, as well as a network of kiosks dedicated to the new bank. However, an HSBC spokeswoman says it is too early to say how many are planned or what format they would take.
The new bank will target customers with about $100,000 (£63,000) earmarked for investment, and offer competitive rates on its savings accounts and services.
The spokeswoman says it is too early to say whether the new company will appoint an external agency and set up a new marketing department, or draw on the banks’ current resources.
The new company is expected to dispose of a multi-million pound advertising budget.
The joint venture comes as other UK banks seek to expand their operations into Europe because of increased domestic competition and the relative inexpense of operating a Net company.