In a major step toward a unified European market, the European Economic Community's finance ministers agreed to remove all controls on capital flow within the Common Market starting in 1990. Monday's accord will let EEC citizens open bank accounts and obtain other financial services such as loans in any of the 12 Common Market member nations. EEC officials said this will spur more competition among banks and create a single financial market competitive in size with the United States and Japan. "Creation of this large financial area should make it possible for EEC banks to catch up with the financial centers in Tokyo and New York," said Jacques Delors, president of the EEC's executive commission. The accord figures in the EEC's "Internal Market" plan under which all internal borders that still hamper a free flow of people, goods and services are to be removed by 1992.