Google remedy phase weighs AdX divestiture and open source auction

Google returned to a federal courtroom in Alexandria, Virginia, on Monday as judges begin the remedy phase of a high-stakes antitrust trial over the companys dominance in online advertising technology. U.S. District Judge Leonie M. Brinkema, who in April ruled that Google unlawfully maintained monopolies in the open web display publisher ad server and ad exchange markets, will hear two to three weeks of argument on what steps should be imposed to restore competition.

The Department of Justice and a coalition of states are asking the court to force Google to divest its ad exchange, known as AdX or Google Ad Manager, and to require that the mechanism that decides winners of instant ad auctions be made open source. The government has also proposed a backup remedy that would compel Google to sell its publisher ad server if other measures fail to boost competition within a set period, court filings show. Google collects roughly a 20 percent fee from publishers who sell ad space through AdX, a central detail in the governments case.

Google said the governments proposed fixes are technically unworkable and would create prolonged uncertainty for advertisers and publishers. The company...