Texas Attorney General Greg Abbott is conducting an antitrust review of Google, the search engine giant announced Friday.

Abbott is looking into whether Google intentionally buries search results that might promote its competitors. European antitrust regulators opened a similar investigation in February.

The Texas case involves three companies – Foundem, SourceTool/TradeComet, and myTriggers. Abbott has asked for more information about Google's dealings with these companies, Don Harrison, deputy general counsel at Google, said in a blog post.

According to Google, these companies have ties to Microsoft, and they believe their less desirable rankings on Google is Google's effort to attack the competition.

Foundem is a "British price comparison site that is backed by ICOMP, an organization funded largely by Microsoft. They claim that Google's algorithms demote their site because they are a direct competitor to our search engine," Harrison wrote.

Foundem was also named in the EU case.

Google said SourceTool/TradeComet and MyTriggers, meanwhile, are represented by Microsoft antitrust attorneys. SourceTool/TradeComet filed a private antitrust suit against Google, but it was dismisssd earlier this year. "Independent search experts have called SourceTool a "click arbitrage" site with little original content," Harrison said.

MyTriggers, meanwhile, blamed Google for a recent dip in traffic, but Harrison said the problem was actually related to the overheating servers.

Google made similar claims in the EU case, which Microsoft refuted. Microsoft did not immediately respond to a Friday request for comment.

"We work hard to explain our approach to search and how our ranking works, and we also listen carefully to people's concerns," Harrison concluded. "We're looking forward to working cooperatively with the Texas Attorney General's office, and we strongly believe our business practices reflect our commitment to build great products for the benefit of users everywhere."