T-Mobile US Inc., the most eligible company in the U.S. wireless industry, has another suitor on its hands. Upstart French telecom company Iliad SA on Thursday said it has offered $15 billion for a majority stake. Iliad is injecting itself into the courtship of T-Mobile, the fourth-largest U.S. cellphone carrier, and Sprint Corp., the No. 3. Sprint has reportedly been in talks with T-Mobile for months, but no deal has been announced. Analysts believe U.S. regulators are likely to block the T-Mobile/Sprint pairing due to concerns that it would reduce competition and thus raise prices for consumers. Iliad is much smaller than T-Mobile US, and it doesn't have the financial might to buy the whole company. It's offering $15 billion in cash for 57 percent of T-Mobile US, at $33 per share. That's less than Sprint's reported offer of around $40 per share. T-Mobile confirmed that it received Iliad's proposal and said that it will have no further comment. Iliad said it did not have a response from T-Mobile's board.