In this decision the 9th Civil Chamber of the German Federal Supreme Court changed its case law on the validity of a standard form contract providing a universal guarantee, and followed the 'causation' line of case law of the 5th and 11th Civil Chambers. The judgment was based on the following set of facts: The plaintiff savings bank provided a property company, a Kommanditgesellschaft, with an overdraft. In 1984 the defendant, a shareholder in the company, agreed to become personal guarantor of the credit advanced to the property company under a standard form of agreement with no restrictions on the time period or amount of the guarantee. Under Condition 1(1) of the Conditions of Guarantee, the guarantee was 'to provide security for all existing and future claims of the savings bank against the principal debtor, including conditional and time limited claims, … which arise out of their business relationship (in particular out of overdraft, credit and loan facilities of all kinds and bills of exchange) as well as out of bills of exchange which are submitted by third parties, guarantees, assignments or by way of subrogation.' In October 1985, the defendant parted from the company and in January 1986 the plaintiff raised the company's overdraft facility to 2.5 million DM and in addition granted it loans of 2 million and 1.5 million DM. The defendant gave notice of the termination of the guarantee in 1990, and shortly thereafter the company became bankrupt. The plaintiff claimed a sum of more than 10 million DM from the defendant as guarantor, and asserted an initial part claim in court for 1 million DM. At first instance and on appeal the claim was allowed. An appeal in cassation in the Supreme Court led to the quashing of the decision of the appeal court and the reference of the case back for a rehearing. In a departure from its earlier jurisprudence, the 9th Civil Chamber of the Supreme Court held that the clause in question was invalid, for breach of § 9 of the Law on General Conditions of Contract, and possibly of § 3 of the same Law. § 767 (1) of the German Civil Code required the guarantee to be limited. In a case where an overdraft facility was guaranteed, the extent of the overdraft allowed at the time the guarantee was given provided the limit within the meaning of this provision. The broad declaration of scope contained in the Conditions of Guarantee was by contrast inconsistent with this interpretation of § 767 (1) of the Civil Code and the purpose of the contract, because under it the guarantor was obliged to stand security for new extensions of credit, provided by the lender without any action on the part of the guarantor and exceeding the level of credit authorised by the lender at the time the guarantee was given. In addition, the standard form extension of liability to all existing and future commitments of the principal debtor was entirely surprising if the guarantee was given in order to encourage the grant or maintenance of a specific overdraft of a given amount, or the raising of the overdraft limit to a certain amount (causation principle). The standard form extension of the liability of the guarantor to all existing and future commitments of the principal debtor arising out of its relationship with the bank had not become a part of the contract of guarantee, therefore, but the declaration of scope remained valid in so far as it concerned the overdraft up to the limit agreed at the time the guarantee was given. The clause could therefore be partly maintained: it was not an impermissible reduction of the contract in an attempt to preserve it. The following comments analyse the decision from the point of view of Belgian (De Wilde), Swiss (Belser) and Greek (Tzouganatos) law.