Sprint isn't the only company trying to buy T-Mobile US.

Iliad, a telecom in France, "has made an offer for T-Mobile US in a bold bid to counter an offer for the country's fourth-largest wireless carrier by Sprint," The Wall Street Journal reported today. But it may be too late. While Sprint and T-Mobile haven't announced a merger, the two companies "have agreed on the broad outlines of a deal valuing T-Mobile US at more than $30 billion," the report stated.

The CEO of Sprint owner SoftBank, Masayoshi Son, has argued that Sprint needs more scale to compete against AT&T and Verizon Wireless and has vowed a "massive price war" if regulators let Sprint and T-Mobile merge. T-Mobile US CEO John Legere has spoken favorably of "consolidation" and is reportedly likely to be CEO of a combined Sprint/T-Mobile.

While a Sprint/T-Mobile deal would leave the US with just three major carriers, a purchase by Iliad would preserve the status quo of four, perhaps making it more acceptable to regulators. AT&T previously tried to buy T-Mobile, but the deal was blocked by US regulators. T-Mobile is owned by Deutsche Telekom.

Iliad's offer for Sprint was "made less than a week ago to T-Mobile's board," but "It is unclear what, if any, the response to the bid has been," the Journal wrote.

"Iliad, which has sparked a fierce price war in France's mobile-telephone market via its cutthroat rates, sees the offer as a 'one-time opportunity to enter the world's-largest telecoms market,'" one source told the Journal.