BERLIN, April 23 -- Deutsche Telekom is exploring a possible tie-up with T-Mobile US to create a US$300 billion (RM1.1 trillion) telecoms giant, sources said, in what would overtake Vodafone-Mannesmann's US$203 billion merger in 1999 to become the biggest M&A ‌deal ever.

The German group already controls 53 per cent of the US unit. But a deal would potentially bring both companies under one entity in a bid to reignite growth in a stagnating telecoms sector, according to a person familiar with the situation and Bloomberg, which was first to report the talks yesterday.

A merger would ‌provide scale to compete in both the US and Europe but could also face structural, geopolitical and regulatory challenges, analysts and one indu...