Democratic presidential nominee Hillary Clinton thinks U.S. regulators should closely scrutinize AT&T's acquisition of Time Warner, her spokesman said on Sunday.

Clinton spokesman Brian Fallon told reporters on Sunday there were "a number of questions and concerns" about the deal "but there's still a lot of information that needs to come out before any conclusions should be reached."

"But certainly she thinks regulators should scrutinize it closely," Fallon said.

The U.S. Senate subcommittee on antitrust will hold a hearing sometime this year on AT&T Inc's planned acquisition of Time Warner, a spokesman for the subcommittee's chairman, Mike Lee, said on Sunday.

AT&T announced it plans to buy Time Warner on Saturday for $85.4 billion, raising concerns among U.S. lawmakers about antitrust issues.