The U.S. Justice Department is seeking the final documents to complete an antitrust investigation of Alphabet Inc's Google , said three sources familiar with the probe, which is expected to end with a lawsuit this summer.
State attorneys general have separate probes into Google, and the U.S. House of Representatives Judiciary Committee has ongoing investigations into Google, Amazon.com Inc , Facebook Inc and Apple Inc .
The department has requested information by the end of June from companies concerned about Google's abuse of its advertising clout, as well as those with data that could be used to support a complaint against Google, the sources said, noting that the deadline could be extended.
They did not say what the complaint would allege.
Justice Department officials and some state attorneys general will hold a virtual meeting on Friday to discuss the probe, a person briefed on the matter said.
Google, which provides free web searches, email and other services, makes money through advertising. Google controls a third of the world's online ad spending but 90% of the market for some ad tech tools. This includes Google Ad Manager, software that publishers use to sell space for display ads.
Google has also been accused of abusing its dominance of Android, its smartphone operating system. Platforms such as Yelp say Google favors its own products in search results.
The Justice Department declined to comment. Google had no immediate comment.
The dozens of state attorneys general led by Texas which are also investigating Google will certainly be asked to join the federal lawsuit, and many will likely do so, one of the sources said.
"They're not joined at the hip but there is a lot more coordination," the source said.
Google's defenders, like Washington-based tech trade group NetChoice whose members include Alphabet, say digital ad prices have fallen sharply in the past decade as competition has increased.
The state attorneys general focusing on Google are considering going after the company for privacy lapses by using statutes that bar deceptive practices, according to one source.
State laws barring unfair and deceptive practices can be interpreted broadly and sometimes carry heavy financial penalties, especially if the number of violations is large. Arizona and New Mexico already have sued Google over allegedly deceptive privacy practices this year, seeking $10,000 and $5,000 respectively per violation of their state statutes.
The government's probes of Google bear striking similarities to its probe of Microsoft Corp in the 1990s when it provided the dominant operating system. Like Microsoft, Google was first investigated by the Federal Trade Commission. In both instances, the Justice Department and the states then began their probes.
The Justice Department won a trial against Microsoft in 1998 which was overturned on appeal and remanded. The two sides settled in 2001.