An international banking network in which Electronic Data Systems Corp.  plays a key role, has signed its first Scandinavian member. 
Unibank, the second-largest bank in Denmark, becomes the sixth in Europe  to join the Ibos Association. Members get access to technology that allows   them to offer services collaboratively across national borders.   
  
Such territorial expansion is crucial to Ibos, which wants to put  together a multinational "virtual bank" designed for the increasingly   integrated European market.   
Other members of the consortium are Royal Bank of Scotland, Banco  Santander of Spain, Banco de Comercio e Industria of Portugal, Credit   Commercial de France, and Kredietbank of Belgium.   
  
Also participating are Credit General, a Belgian affiliate of  Kredietbank, and First Fidelity Bancorp. of the United States, which signed   on last July.   
The network grew out of the close corporate ties between Royal Bank of  Scotland and Banco Santander, which own stock in each other, and Electronic   Data Systems, the data processing giant owned by General Motors Corp.   
Royal Bank and Santander - the latter also owns a piece of First  Fidelity, which happens to rely on EDS for operating support - launched   Ibos as Interbank On-line System in 1991. EDS joined them with an equity   stake in the administrative entity Ibos Ltd. last year.     
  
Goldman, Sachs & Co., the U.S. investment bank, also took a minority  interest. 
Ibos revolves around on-line, or real-time, access to such services as  currency exchange and funds transfers, as well as to account information. 
Unibank, which is based in Copenhagen, sees Ibos as "a very attractive  addition" to its international services, "particularly real-time cash   management for large corporate customers," said Lars Eskesen, deputy chief   executive.     
"At the same time, Unibank in Scandinavia will be able to provide first-  class corporate support for the customers of our partner banks in the Ibos   Association," Mr. Eskesen said.   
  
John Bertrand, managing director of Ibos Ltd. in London, said Unibank is  certain to benefit from its membership, in that it is the primary bank for   30% of all large enterprises in Denmark, a European Community member.