FILE PHOTO - The AT&T logo is pictured during the Forbes Forum 2017 in Mexico City, Mexico, September 18, 2017. REUTERS/Edgard Garrido

WASHINGTON (Reuters) - The U.S. Department of Justice and AT&T Inc T.N have held unsuccessful settlement talks over the wireless and pay-TV company's bid to buy movie and TV show maker Time Warner Inc TWX.N, the two sides said in a court filing on Friday.

The Justice Department has sued to stop AT&T, owner of DirecTV and the No. 2 U.S. wireless company, from buying Time Warner for $85 billion because of concerns that it could raise prices for rivals and pay-TV subscribers and hamper the development of online video.

A trial to decide the matter is set to begin on March 19, and run about 15 days, according to the filing.

The two sides noted in the filing, which set out an agreed schedule leading up to the March trial, that there had been unsuccessful settlement discussions between the two.

“All parties have engaged in good-faith settlement negotiations, but despite their efforts, have not been able to settle the matter,” the filing said.

In an effort to help reach an agreement, AT&T and Time Warner last month offered to use licensing terms that forbid Time Warner’s Turner unit from “going dark” on any distributor for seven years after the deal closes if they were to reach an impasse in negotiations.

In preparation for the trial, final fact witness lists will be exchanged by Feb. 2 and all pretrial motions should be filed by March 12, according to the court filing.