A pair of top Trump administration antitrust enforcers on Tuesday acknowledged friction between their agencies amid a sweeping investigation into the giants of the tech industry, conceding that turf battles have played out over which companies from each side will probe for any anticompetitive conduct.

Appearing together before a panel of the Senate Judiciary Committee, the leader of the Justice Department’s antitrust division and Joseph Simons, chairman of the Federal Trade Commission, testified that a longstanding power-sharing agreement has been strained as the two agencies hash out how to divide up investigations of companies including Facebook Inc. and Alphabet Inc.’s Google, along with Apple and Amazon.