Credit: CC0 Public Domain

More than half of state attorneys general are planning to open an antitrust investigation of Alphabet Inc.'s Google next week, according to two people familiar with the matter.

Multiple states are planning to announce the coordinated probe on Sept. 9, said three people, who asked not to be identified discussing sensitive deliberations. The plans could change.

U.S. have already taken preliminary steps toward a probe of the search giant, which is also a major player in online ads and mobile operating systems. It has faced antitrust investigations in Europe as well.

The Washington Post previously reported the state investigation. It was not immediately clear what the probe would focus on or which states would participate.

A group of state attorneys general said in June at an enforcement workshop hosted by the Federal Trade Commission that they are examining a wide range of practices, including , digital advertising and innovation, among large tech companies.

Google spokesman Jose Castaneda said the company continues "to work constructively with regulators, including attorneys general, in answering questions about our business and the dynamic technology sector."