(Reuters) - The European Commission will open a formal in-depth probe soon into Abu Dhabi-based Emirates Telecommunications's (e&) proposed acquisition of Czech PPF group's telecoms assets in Bulgaria, Hungary, Serbia and Slovakia, the Financial Times reported on Saturday.

While the precise timing remains uncertain, the announcement of the investigation is expected to come as early as Monday, the FT said, citing three people with direct knowledge of the case.

E& had last year agreed to pay 2.2 billion euros ($2.38 billion) to acquire a controlling stake in Czech PPF Group's telecoms assets in Bulgaria, Hungary, Serbia and Slovakia.

($1 = 0.9259 euros)

(Reporting by Rishabh Jaiswal in Bengaluru; Editing by Kim Coghill)