John Legere, chief executive officer and president of T-Mobile US Inc., left, listens as Marcelo Claure, chief executive officer of Sprint Corp., speaks during an interview on the floor of the New York Stock Exchange (NYSE) in New York, U.S., on Monday, April 30, 2018.

The U.S. Department of Justice will on Thursday announce its approval of the $26 billion merger deal between T-Mobile and Sprint conditional on the sale of certain wireless assets to Dish, people familiar with the matters told CNBC's Andrew Ross Sorkin.

People familiar with the discussion told CNBC's David Faber that Dish will pay $1.4 billion for T-Mobile's prepaid mobile business and $3.6 billion over time for spectrum assets. Those people added that T-Mobile and Sprint still expected to generate $43 billion in synergies as a result of the tie-up.

The Justice Department officials initially wanted T-Mobile and its parent company, Deutsche Telekom, to sell assets like wireless spectrum licenses and make other promises to help conserve competition in the cellular market.

That received some pushback from T-Mobile, which wanted to limit Dish's spectrum capacity to 12.5%, people familiar with the matter told CNBC's Faber earlier in July. Deutsche Telekom also wants to limit any strategic Dish investor to 5%, the sources added.

Sprint rose 8%, T-Mobile rose 3.1% while Dish dropped about 3.9% in trading Wednesday.