AT&T agreed in a court filing Tuesday that Sprint-Nextel's lawsuit against the $39 billion AT&T/T-Mobile USA merger should begin after trial in a prior antitrust lawsuit brought against it by the U.S. Department of Justice is completed.

The Dallas-based company agreed to the case timeline in order to avoid interference with the litigation of and trial of the DOJ Action, and the resulting prejudice to defendants, the filing provided to the International Business Times said.

In a separate filing, Sprint agreed to a trial beginning following the Justice Department case, Bloomberg reported. Both AT&T and Sprint declined to comment to the IBTimes on the filings.

The case involving the Justice Department is slated to begin Feb. 13 in U.S. District Court in Washington. The department filed a lawsuit to block the proposed merger last August, citing concerns over the deal's benefit to consumers.

Sprint, based in Overland Park, Kan.,the third largest wireless carrier in the U.S. behind Verizon Wireless and AT&T, filed its lawsuit on Sept. 6. C Spire Wireless, a small regional carrier, also filed a lawsuit against AT&T and Deutsche Telekom, the parent company of T-Mobile USA, on Sept. 19.

If the two wireless carriers were to merge, they would create the largest wireless carrier in the U.S.

A hearing before Judge Ellen Huvelle regarding all three antitrust cases is set for Dec. 9.

Shares of AT&T rose 0.45 percent to $29.28 in mid-afternoon trading. Shares of Sprint fell 2.83 percent to $2.58.