The deal will bring classics like George Orwell's "1984" and the recent literary phenomenon "Fifty Shades of Grey" by E.L. James under one umbrella. The merged publisher Penguin Random House is set to control about a quarter of the world's consumer book market.
Still, the deal does "not raise competition concerns, in particular because the merged entity will continue to face several strong competitors," the EU Commission said in a statement.
The decision follows a similar unconditional green light by U.S. antitrust authorities in February. The Canadian Competition Bureau and other regulators are still reviewing the deal's impact.
Random House's German parent company, Bertelsmann SE, welcomed the EU's decision in a statement, calling it "another important stage" toward completing the merger.
Bertelsmann will own 53 per cent of the new company, which will encompass all of both companies' publishing units in the U.S. and six other countries.
Random House and Penguin, a division of Britain's Pearson PLC media group, are two of the so-called "big six" publishers in the U.S.
The merger is widely seen as an effort to counteract the power of Amazon.com, which has worried publishers by aggressively cutting prices on e-books.
Besides the U.S., the proposed merger includes Random House and Penguin Group's publishing units in Canada, the United Kingdom, Australia, New Zealand, India and South Africa. Penguin's operations in China and Random House's publishers in Spain and Latin America also are part of the proposed merger.
The combined company will control 26 per cent of the global consumer publishing market, leaping ahead of the 17 per cent share of French publisher Lagardere, according to analyst estimates.
The two media companies had announced the merger last October and expect to finalize the deal in the second half of this year.