The move gives potential suitors time to wait for a more favorable political environment toward telecoms mergers.
The US Federal Communications Commission is to start an auction for low-frequency airwaves at the end of this month and this could last for months. While this is happening, it is unlikely that there will be many mergers.
Auction participants are not allowed to engage in any partnership or merger talks during the weeks before and after the bidding process. T-Mobile US, which is 65.4 percent owned by DT has said it could spend up to $10 billion in the auction.
An auction of AWS-3 airwaves, which ended early last year, raised a record $44.9 billion.
DT has been trying to sell the unit for years, hoping to cash in on a recovery in the business.
Last month T-Mobile US’s net profit nearly tripled in the fourth quarter after it added more than 2 million customers. Last year it overtook Sprint to become the third largest provider.
But attempts to sell T-Mobile to Sprint in 2014 were blocked by US regulators and last year talks between T-Mobile US and Dish Network stalled.