BRUSSELS, March 22 (Reuters) - EU antitrust regulators have resumed their investigation into British Airways owner IAG's 400-million-euro ($432.7 million)) bid to buy out Air Europa, according to an update on the European Commission website.

The EU competition enforcer had paused its investigation on Feb. 9 while waiting for the companies to provide information it had requested.

The Commission, which restarted the clock last week, set a new deadline of July 15 for its decision.

IAG is likely to get a statement of objections shortly from the Commission setting out its concerns on potential anti-competitive effects of the deal, people familiar with the matter told Reuters last month, after remedies the airline proposed were considered insufficient.

The EU watchdog has toughened its policy towards airline mergers, demanding that carriers cede airport slots and routes to rivals able to operate them almost immediately in return for its approval.

($1 = 0.9244 euros) (Reporting by Foo Yun Chee Editing by Mark Potter)