Facts
Swiss citizen Dr. rer. pol. J. Rothenberger founded the WAMEX GmbH, a laundry machinery factory, in Düsseldorf in 1955. By contract dated June 5/9, 1959, Gefa, Gesellschaft für Absatzfinanzierung m.b.H., Wuppertal-Elberfeld, undertook to "grant loans to creditworthy buyers of the resellers of the WAMEX company for the purchase of durable goods" within a certain credit limit. Pursuant to § 6 of the contract, the WAMEX company assumed the joint and several guarantee for all obligations of the buyers under such loan agreements.
By contract dated June 11, 1959, concluded in Düsseldorf, Rothenberger assumed the joint and several guarantee for all claims that Gefa might have against the WAMEX company he controlled "from the granting of loans in any form or manner, from current account, from bills of exchange or other transactions, now or in the future". Wuppertal was designated as the place of performance for Rothenberger's obligations under this guarantee, and the law applicable there was declared to be decisive.
On the basis of its guarantee obligation of June 5/9, 1959, WAMEX had to stand in for losses in the amount of DM 11,686.52 that Gefa had suffered from loans to buyers of washing machines. However, WAMEX went bankrupt in May 1963.
Gefa sued Rothenberger based on his guarantee obligation of June 11, 1959, for payment of the above-mentioned amount plus 8% interest since August 10, 1964.
Considerations
The Federal Court first examined the admissibility of the appeal. Since the parties had designated the law applicable in Wuppertal, i.e., German law, as decisive in the guarantee contract of June 11, 1959, the validity of this choice of law under Swiss law is undisputed.
The defendant argued that the enforcement of the guarantee claim existing under German law in Switzerland was excluded, as the…