Facebook will unconditional EU approval for its $19 billion (12 billion pounds) offer for WhatsApp in a deal pitting it against telecoms operators, two people familiar with the matter said on Thursday. The landmark acquisition will give the company a firm foothold in the fast-growing mobile messaging market. A plan by WhatsApp to add free voice-call services for its 450 million customers later this year, however, makes it a potentially powerful competitor to companies such as Deutsche Telekom, Telecom Italia and Telefonica.