Maersk unveiled the proposed tie-up with Switzerland-based MSC Mediterranean Shipping Company and France's CMA CGM CMACG.UL, called the P3, in March.

The companies agreed to pool about 250 ships which will operate on three trade routes, Asia-Europe, trans-Pacific and trans-Atlantic in order to cut costs.

That deal followed a Far East-Europe alliance called G6, which was set up in late 2011 and includes Nippon Yusen Kaisha, and triggered scrutiny from the European Commission.

The EU watchdog said on Tuesday it did not plan to take any action against either alliance.

"At this stage, the Commission does not intend to open proceedings in relation to P3 or G6," said Antoine Colombani, Commission spokesman for competition policy.

"The Commission will follow market developments and will remain vigilant as regards any risks for competition that may arise from the implementation of P3 or G6. The Commission will consider intervening if necessary," he said.

U.S. regulators cleared the P3 in March.

The G6 is made up of world No. 5 Hapag-Lloyd HPLG.UL, APL, Hyundai Merchant Marine 011200.KS, Mitsui O.S.K. Lines, Nippon Yusen Kaisha and Orient Overseas Container Line.

The partnership has more than 90 ships in nine services calling at more than 40 ports in Asia, Europe and the Mediterranean.

(Reporting by Foo Yun Chee; Editing by Erica Billingham)

By Foo Yun Chee