The World Trade Organization (WTO) on Tuesday formally started to use the name "European Union (EU)" as the Lisbon Treaty came into force. Previously, for legal reasons the EU was known officially in the WTO as the European Communities (EC).

"For the first time in the WTO, the name 'European Union' was used" at an ongoing WTO ministerial conference, the Geneva-based body said in a statement.

But the name EC will continue to be found in older documents, it said.

The Lisbon Treaty came into force on Tuesday across the 27-nation European Union. It will allow the bloc to be able to speak with one stronger voice on the international stage.

The EU (until Nov. 30 known officially in the WTO as the EC), as a single customs union with a single trade policy and staff, has been a WTO member since Jan. 1, 1995. Its 27 member states are also WTO members in their own right.