T-Mobile US will reportedly reject Iliad’s $15 billion bid by Laura Lorenzetti @FortuneMagazine August 5, 2014, 2:18 PM EDT E-mail Tweet Facebook Google Plus Linkedin Share icons T-Mobile US TMUS plans to turn down Iliad’s $15 billion takeover bid as Sprint prepares its own offer for the U.S.’s smallest mobile phone carrier, Bloomberg News reported. Iliad, helmed by billionaire owner Xavier Niel, made the all-cash offer on July 31. The deal, if consummated, would give the French telecommunications company a 56.6% ownership of T-Mobile US. Meanwhile, Sprint S , which is controlled by Japan-based Softbank, has quietly been putting together a $40-a-share offer, according to the report. Such a combination, of the No.3 and No.4 cellular carriers, would face heightened U.S. regulatory scrutiny. The two foreign-owned companies have been eyeing T-Mobile as a way to tap into the $195 billion U.S. mobile phone industry, which is expected to continue to grow as demand for data services surges. Deutsche Telekom, which owns 67% of T-Mobile, felt Sprint’s bid would be more competitive than Iliad’s offer, although the parent company would consider a lower offer if it avoids a long antitrust battle, people with knowledge of the matter told Bloomberg. Deutsche Telekom may not want to rehash the failed 2011 AT&T bid, when the U.S. Federal Communications Commission and the Department of Justice shut down the $39 billion deal. While Iliad would face less regulatory scrutiny, shareholders may be wary that an increased bid could put pressure on the company’s finances. T-Mobile’s market capitalization of $27.1 billion makes the company worth almost twice Iliad’s value.