A month after losing a landmark antitrust case brought by the Department of Justice, Google is headed back to court to face off for a second time against federal prosecutors.

Google this year offered to sell its advertising marketplace Ad Exchange, or AdX, to end an EU antitrust investigation. But European publishers rejected the proposal, Reuters reported this week . The news agency cited two people with knowledge of the matter but did not name them.

Alphabet's Google took a major step this year to end an EU antitrust investigation with an offer to sell its advertising marketplace AdX but European publishers rejected the proposal as insufficient,

In an effort to quell monopoly concerns in the EU, Google reportedly offered to sell its AdX advertising marketplace. Sources told Reuters that European publishers rejected Google's offer, arguing that the company would have to divest more in order to dismantle the conflicts of interest in its online advertising operations.

Following a complaint from the European Publishers Council, the European Commission opened its investigation of the search giant, charging Google with violating its antitrust laws by using its advertising technology to undermine and unlawfully block rivals.

Alphabet's Google earlier this year offered to sell its advertising marketplace AdX to allay EU competition concerns over its adtech practices but the proposal got short shrift from European publishers,