Days after the Department of Justice sued to block AT&T's proposed $39 billion acquisition of T-Mobile, AT&T is reportedly prepared to make some big concessions to get the deal done.

According to Reuters, AT&T is willing to sell off 25 percent of T-Mobile's business and promise not to raise existing T-Mobile prices, in order to mollify antitrust authorities and seal the acquisition.

The key argument raised in the DOJ's lawsuit on Wednesday was that the merger would substantially lessen competition, putting 90 percent of the wireless market in the hands of three companies: AT&T, Verizon Wireless, and Sprint (or a "duopoly," if you ask Sprint).

But by selling 25 percent of T-Mobile's spectrum, airwaves, and customer base, AT&T might be able to convince District Judge Ellen Segal Huvelle to let the merger pass.

"AT&T is pretty determined that they can find a solution, and they are pretty confident," a source told Reuters.

As PC Mag's lead mobile analyst Sascha Segan noted earlier, although T-Mobile is the smallest of the current "big four" carriers with 33 million customers, that is still more than the next 10 carriers combined. DOJ documents also say that AT&T would control more than 50 percent of 17 metro U.S. markets if the acquisition went through.

The federal court now has to rule on the DOJ's suit, while the Federal Communications Commission is also still considering the deal. AT&T said it plans "to ask for an expedited hearing so the enormous benefits of this merger can be fully reviewed." AT&T has an incentive to make the deal work: if it fails, AT&T has to pay T-Mobile up to $6 billion in cash and other assets.

AT&T declined to comment on the Reuters report.

For more, see AT&T, T-Mobile Merger: Job Killer or Creator?, as well as On AT&T/T-Mobile Merger, Justice is Served and the seven alternative buyers for T-Mobile slideshow below.