FRANKFURT, June 23 (Reuters) - The European Central Bank secured key parliamentary backing on Tuesday for the launch of a digital euro, an electronic means of payments aimed at making the euro zone less reliant on U.S. credit cards at a time of fraying transatlantic relationships.

The approval of draft rules by the economic committee of the European Parliament comes after three years of wrangling between the ECB and banks, which have been worrying about deposit outflows and lost revenues and sought to limit the scope of the project.