London, Feb. 18--Approval of the United States Supreme Court's rulings in the momentous gold clause cases was expressed in most of Europe's financial capitals tonight.

The cause of international currency stabilization was believed to have been advanced appreciably by the upholding of the Roosevelt Administration's monetary policies.

The news reached London after the Stock Exchange had closed, but there was wild excitement in the "Street" market, where lively trading brought sharp advances in American stocks, particularly rails.

The dollar slumped in European foreign exchange dealings. Sterling was quoted here at $4.89 immediately after cables flashed the Court's action, compared with $4.86 5-16 previously. In Paris, Francs rose from 15.20 to the dollar ($.0658 a franc) to 15.10 (franc $.0662).