BERLIN, June 21 (Reuters) - Apple (AAPL.O) became the fourth major digital company to face closer scrutiny from Germany"s antitrust watchdog on Monday after the cartel office said it had launched an investigation into whether the tech giant is exploiting its market position. The Bonn-based watchdog said it will examine whether Apple has "paramount significance across markets" that thwarts competition. "A key focus of the investigation will be the operation of the App Store, as in many cases it empowers Apple to influence the operations of third parties," said Andreas Mundt, president of the Federal Cartel Office (FCO). The watchdog has made use of enhanced powers gained under recent reforms to Germany"s competition laws to open investigations into Alphabet"s Google (GOOGL.O), Facebook (FB.O) and Amazon (AMZN.O) over their data practices. read more Further proceedings against Apple are also being considered with regard to complaints received about potentially anti-competitive practices, the watchdog said. These include a complaint that Apple gives itself preferential treatment by pre-installing its own applications, the watchdog said. An Apple spokesperson said the company"s App Store has given German developers of all sizes the same opportunity. "We look forward to discussing our approach with the FCO and having an open dialogue about any of their concerns," the spokesperson added.