Siemens-Nixdorf Informationssysteme AG has decided to make the Ungermann-Bass subsidiary of Tandem Computers Inc its preferred local area network equipment supplier. Under the agreement Siemens-Nixdorf will resell Ungermann-Bass products worldwide with its own products, and the companies say that Ungermann-Bass was chosen over 36 other hub vendors vying for the deal because of the technical superiority of its recently announced switching-based hub architecture. The Access/One enterprise hub uses plug-in system modules to provide access to enterprise-wide resources over standard telephone wire and new backplane extensions move the hub from a local network-based architecture to a switching-based infra structure. The agreement marks the beginning of an on-going relationship and will include future joint marketing and technology announcements. No value was put on the agreement.