Amazon's Jeff Bezos, Apple's Tim Cook, Facebook's Mark Zuckerberg and Google's Sundar Pichai will appear July 27.
The committee has reportedly already talked with another tech executive ahead of the meeting.
Brad Smith, president and chief legal officer of Microsoft, was interviewed via videoconference, according to The Information.
The Information went on to say the Microsoft executive discussed his company’s concerns about how Apple operates its App Store.
FOX Business has reached out to Microsoft for comment.
Regulators for both the U.S. and Europe have been looking at that issue involving Apple.
The hearing is part of an ongoing investigation into competition in the digital marketplace.
Last week, the New York Times reported that Amazon would be making Bezos available to testify at the hearing.