Indonesia, Malaysia and the Philippines yesterday agreed to designate a transit corridor for commercial vessels in the seas between Sabah, the southern Philippines and Indonesia's Sulawesi Island.
The move is aimed at curbing a spate of hijackings by Islamist militants in the Sulu and Celebes seas.
Nearly 20 Indonesian and Malaysian tugboat crew have been kidnapped by Abu Sayyaf militants this year. Kidnappings over the last 15 years have made the Abu Sayyaf notorious, with extorted ransoms running into millions of dollars.
The three countries also agreed to step up air and sea patrols and escorts for commercial ships in common maritime areas.
It was the second meeting of officials of the three countries to tackle growing regional security challenges after their foreign ministers met in Jakarta last month.
In 2002, Indonesia, Malaysia and the Philippines signed a pact to strengthen security against growing cross-border attacks by Abu Sayyaf militants. But they had not set up coordinated naval patrols, with navies operating in their own territorial waters.
Analysts say US$40 billion (S$54 billion) worth of cargo passes through the Sulu and Celebes seas each year.