NEW YORK ( TheStreet) -- Google ( GOOG) is said to be in acquisition discussions with popular daily deal site Groupon for as much as $6 billion, according to DealBook. A deal could be reached as early as this week, and would be one of Google's largest acquisitions ever. In other Google news, the European Union is opening an anti-trust investigation into the giant's search practices, said The New York Times. Complaints from three competitors citing that Google treats rivals' results differently from its own in displaying search results triggered the investigation, which Google said it would fully cooperate with. Shares of Google fell 1.2% to $575 in pre-market trading Tuesday. Seagate Technology ( STX) has ended takeover discussions with private equity bidders, claiming the valuation was not in the best interest of shareholders, the company said Monday. Shares of Seagate were down 4.8% to $13.20 in pre-market trading. Microsoft ( MSFT) has sold 2.5 million Kinect units since the device launched less than a month ago, the company said Monday. Kinect, a controller-free accessory for the Xbox, is forecast to sell 5 million units this holiday season. It sold 1 million units in the first 10 days of its release. Shares of Microsoft were down 0.5% to $25.18 in pre-market trading. News Corp ( NWSA) is open to exploring options for MySpace including a sale, COO Chase Carey said at a media conference Monday. MySpace has struggled to remain relevant in the social networking space as users have migrated to Facebook. News Corp is in the process of overhauling MySpace and transitioning the site to focus more on music and entertainment. Travel Ad Network has acquired Travel Muse, a trip planning and research site, the company announced Tuesday. Travel Ad Network has raised $31 million in funding from investors including StarVest Partners, Rho Venture and Village Ventures. --Written by Olivia Oran in New York. >To follow the writer on Twitter, go to http://twitter.com/Ozoran.