Sen. Amy Klobuchar (D-Minn.) and Rep. Spencer Bachus (R-Ala.), Capitol Hill’s top antitrust watchdogs, have vowed to hold hearings on the $45 billion agreement Comcast Corp. reached to buy Time Warner Cable Inc., saying the deal needs congressional scrutiny.

Klobuchar and Bachus, who lead their respective chambers’ antitrust panels, didn’t say when they would have their hearings on the proposed merger of the two largest cable companies in the United States. But the lawmakers said their hearings will examine how the combined company announced Thursday would affect consumers and the marketplace.