T-Mobile (TMUS) Stock Falls on Deutsche Telekom Merger Report

TLDR

• Deutsche Telekom, which holds a 53% stake in T-Mobile, is exploring a full merger of the two companies.
• The deal could create a company worth nearly $300 billion — potentially the largest public merger on record, surpassing the 1999 Vodafone-Mannesmann deal.
• T-Mobile (TMUS) fell around 3.5% on Wednesday; Deutsche Telekom dropped roughly 5%.
• A new holding company would make an all-share offer for both firms, listing in both the U.S. and Europe.
• Any deal would face regulatory review in both Germany and the U.S., and requires political support from both governments.

Deutsche Telekom is exploring a full merger with T-Mobile US in what could become the largest public merger ever recorded. The talks are at an early stage, according to two people familiar with the matter cited by Reuters.

T-Mobile US, Inc., TMUS

The German telecom giant already owns 53% of T-Mobile. Under the reported proposal, a new holding company would make an all-share offer for both firms and list on exchanges in both the U.S. and Europe.

The combined company could carry a market cap of nearly $300 billion, with more than 200 million mobile subscribers. That would make it the world’s most valuable telecoms group.

If completed, the deal would surpass the $202.7 billion Vodafone-Mannesmann merger announced in 1999 — currently the biggest public deal on record, per LSEG data. Deutsche Telekom’s current market value sits at around $166 billion, while T-Mobile is valued at roughly $218 billion.

T-Mobile stock fell around 3.5% on Wednesday afternoon following the Bloomberg report. Deutsche Telekom dropped close to 5%. T-Mobile had closed Tuesday down 1.5% at $195.39.

Both companies declined to comment. T-Mobile said it does not comment on “speculation regarding corporate activity.” Deutsche Telekom said it does not comment on “rumors and speculation.”

Regulatory Hurdles Ahead

Any deal comes with a long to-do list on the regulatory side. The German government and state lender KfW together hold about 28% of Deutsche Telekom. That stake would be diluted in a merged group — potentially below the 25% threshold German authorities have previously flagged as a floor for “strategic businesses,” according to BNP Paribas analyst Sam McHugh.

In the U.S., the deal would likely face antitrust and national security reviews. Policy adviser Blair Levin of New Street Research said the deal is unlikely to be blocked outright, but those reviews give regulators room to seek concessions. FCC Chairman Brendan Carr would be among the key gatekeepers.

William Kovacic of George Washington University’s Competition Law Center noted that Deutsche Telekom’s existing majority stake likely reduces antitrust concerns on the U.S. side.

The backdrop adds complexity. Germany and the U.S. are navigating strained relations tied to tariffs and geopolitical tensions, which could make a deal politically sensitive.

The Strategic Logic

T-Mobile has become an increasingly important driver of Deutsche Telekom’s overall performance. The U.S. market offers stronger growth compared to Europe, where telecoms operate in fragmented, debt-heavy conditions.

Morgan Stanley analysts said the scale of a combined group could support further acquisitions and improve access to capital markets. PP Foresight analyst Paolo Pescatore described T-Mobile as the “engine” of Deutsche Telekom, and said the real appeal of a merger is gaining control while preserving T-Mobile’s valuation upside.

T-Mobile CEO Srini Gopalan previously served as CEO of Deutsche Telekom. Deutsche Telekom CEO Timotheus Hoettges currently chairs T-Mobile’s board.

T-Mobile’s stock has lost about a quarter of its value over the past year. Deutsche Telekom is down roughly 10% over the same period.