(Reuters) – European Union antitrust regulators will decide by Oct. 3 whether to clear world No. 1 online social network Facebook’s $19 billion offer for mobile messaging startup WhatsApp, the European Commission said on Monday. Facebook requested EU approval last week, the Commission’s website showed. The EU competition watchdog can either clear the deal unconditionally, demand concessions or extend the preliminary review into a wider probe. Facebook expects to close the deal, its largest in its 10-year history, this year. U.S. regulators cleared the takeover in April, telling WhatsApp to stick to its current privacy practices after the merger, including not to use users’ personal data for targeted ads.