Candy maker Mars' takeover of Pringles maker Kellanova was cleared by U.S. antitrust regulators on Wednesday, but their EU counterparts opened a full-scale investigation into the $36 billion deal, saying it could lead to price hikes.

The FTC on June 25 announced it granted an early termination of its probe into the nearly year-old Mars-Kellanova transaction. Earlier in the day, the EC — the executive branch of the European Union (EU) — said it has launched an “in-depth investigation” of the planned acquisition, citing competitive concerns under the EU Merger Regulation.

European Commission officials set an Oct. 31 deadline to make a decision on the probe.