WASHINGTON (Reuters) - AT&T Inc was confident it would win regulatory approval for its $85.4 billion acquisition of Time Warner Inc TWX.N before year's end as the Justice Department continues its review, but was still awaiting details about any final requirements for the deal, a senior executive said.

FILE PHOTO: An AT&T sign is seen outside a branch in Rolling Meadows, Illinois, U.S., October 24, 2016. REUTERS/Jim Young/File Photo

Bob Quinn, AT&T's T.N senior executive vice president for external and legislative affairs, said in a C-SPAN interview this week that the telecommunications company was unclear what final conditions the Justice Department may seek as part of any approval.

“That conversation is just beginning really,” Quinn said. “We’ve gotten through the point where we’re produced all the data and answered all the questions and I think that process will kick off this summer.”

In June, a Senate panel voted 19-1 to advance the nomination of Makan Delrahim, who was chosen by President Donald Trump to be the top U.S. antitrust regulator. The Senate must still vote to confirm Delrahim and it is not clear when they will vote.

Until Delrahim is confirmed, “it is kind of hard to predict whether even the list that we see preliminarily will be the final list that they want to close on,” said Quinn, without elaborating.

The No. 2 U.S. wireless carrier still needs some foreign approvals. In March, it won the European Commission’s nod for the deal.

Separately, a group of Senate Democrats on Wednesday, including Bernie Sanders, Elizabeth Warren and Al Franken, urged the Justice Department to closely scrutinize the deal.

“We have strong concerns that the combined company’s unmatched control of popular content and the distribution of that content will lead to higher prices, fewer choices, and poorer quality services for Americans,” they wrote.

“Before initiating the next big wave of media consolidation, you must consider how the $85 billion deal will impact Americans’ wallets, as well as their access to a wide range of news and entertainment programing.”

AT&T said in a statement it had previously addressed all the issues in the letter and argued that the deal would offer consumers more choice, and “will expand distribution and creative opportunities for diverse and independent voices.”