The Federal Trade Commission disclosed late Tuesday that it had ordered Apple, Facebook, Amazon, Google's parent company and Microsoft to release details about past acquisitions, casting a wider net in their investigation of the country's powerful tech companies.

The FTC wants information from the five tech giants - whose total market value exceeds $5 trillion - on their corporate acquisitions that date back 2010 and bypassed a review by the regulators under the Hart-Scott-Rodino Act.

The initiative will enable the FTC to dig deeper into acquisitions made by the tech companies, and to evaluate whether government authorities are getting "adequate notice of transactions that might harm competition," FTC Chairman Joe Simons said. 

In a statement, Simons added that the inquiry will help the commission to continue to keep tech markets open and competitive for the benefit of consumers.

While the investigation is not a formal law enforcement action, Simons explained that "all options are on the table" and, depending on what the commission discovers, it could mandate the companies to reveal past acquisitions or change their corporate practices.

The FTC said it had asked for information on hundreds of smaller acquisitions undertaken by the tech firms in the last 10 years that were not required to be divulged to regulators and could shed light into antitrust violations.

Simons said there is no financial threshold for the degree of the deals that the FTC plans to examine. The request came out of the commission's court proceedings in 2019 regarding transactions among tech companies.

Facebook, Google (whose mother company is Alphabet) and others have acquired many smaller tech companies in the past few years, many of them for just under $100 million. Microsoft, for its part, had eluded any probe after surviving its own antitrust battles with regulators in the days of the dot-com boom and bust.

The actions ramp up the probe in Washington of the country's biggest tech empires. The Department of Justice, House of Representatives and district attorney generals are also looking into whether Amazon, Apple and others acted in an anti-competitive way in many different areas.

The FTC has made similar demands for details from the retail and pharmaceutical industries to investigate how companies used ad strategies, for instance, to thwart consumers.

But the request for information about past mergers was the first by the TFC for the country's tech giants. Shares in all five tech firms plunged during mid-day sessions immediately after the FTC announcement.