The U.S. Federal Trade Commission is looking into whether Facebook Inc. has acquired companies that could have become competition for it, The Wall Street Journal reported, citing sources.

The investigation is said to be part of the FTC's antitrust probe into the social media company.

In a July 25 filing, Facebook said the FTC informed it of an investigation "in the areas of social networking or social media services, digital advertising and/or mobile or online applications."

Facebook has acquired about 80 companies since 2007.

The news also follows Facebook agreeing to pay a $5 billion settlement agreement with the FTC for violating a 2012 order related to its user data practices.