Antitrust regulators from the European Commission (EC) announced this morning that Penguin has joined four other book publishers in accepting a legally binding agreement to address charges that it artificially raised the price of ebooks in collusion with Apple. The agreement wraps up a European Union (EU) antitrust case that was almost identical to a similar, just-resolved antitrust case in the United States.

In both the US and EU cases, all parties save one agreed to terms very quickly. In the United States, the holdout was Apple, and that firm was just found guilty of orchestrating a conspiracy with publishers to artificially and illegally raise the prices of ebooks, harming competitors and consumers. In the EU, Apple and four of the charged publishers immediately settled the antitrust suit, leaving Penguin to face an antitrust investigation alone. And this week, Penguin capitulated.

Related: "EU Demands More Concessions from Google"

“After our decision of December 2012, the commitments are now legally binding on Apple and all five publishers including Penguin, restoring a competitive environment in the market for ebooks,” EC Competition Commissioner Joaquín Almunia said.

Penguin joined publishers Simon & Schuster, HarperCollins, Hachette Livre, and Verlagsgruppe Georg von Holtzbrinck, as well as Apple, in accepting a legally binding agreement to change its business practices and cease its practice of artificially inflating ebook prices. Now, as before the time when Apple entered the ebook market and began the conspiracy to dethrone Amazon’s Kindle platform, retailers are free to set prices on ebooks.

“The Commission has concluded that the commitments offered by Penguin, the other four publishers, and Apple will contribute to creating a favorable environment for a reset of the competitive conditions in the ebooks market during a sufficient period of time,” an EC announcement notes. And while the publishers and Apple settled to avoid an outright finding of guilt, should any infringe on their legally binding agreements with the EU, they will then be subject to fines of up to 10 percent of their annual revenues. This fine is identical to that which would be levied in the event of a guilty verdict.

Related: "Apple Found Guilty of Antitrust Abuse in eBook Collusion Trial"