The long-awaited trade deal between South American bloc Mercosur and the European Union took effect Friday, at least provisionally. The initiative creates a trans- Atlantic market estimated at $22 trillion with 720 million potential consumers, and some nations expect to boost their exports by more than 10% by 2038, once it is fully implemented.

The trade deal was signed Jan. 17 at a meeting of the South American group. European Commission President Ursula von der Leyen 's move to provisionally enact the deal, effectively sidestepping the EU Parliament, is being challenged by EU lawmakers at the bloc’s judiciary.…