
Penta-Ocean Construction Co., Ltd. is a major Japanese general contractor and a world leader in marine construction and dredging. It builds ports, harbours, land reclamation, civil infrastructure and buildings in Japan and overseas, and develops its own construction technology, materials and machinery for technically and geologically challenging projects. It is a member of the International Association of Dredging Companies (IADC).

Company overview
- Founded: April 1896 (incorporated in April 1950)
- Headquarters: 2-8 Koraku 2-chome, Bunkyo-ku, Tokyo 112-8576, Japan
- Net sales: ¥794.3 billion consolidated (FY 3/26)
- Employees: 6,000+ including overseas staff
- Paid-in capital: ¥30,449 million
Expertise
- Marine civil works: ports, harbours, breakwaters and sea bridges
- Dredging and land reclamation, including its own self-propelled trailing suction hopper dredgers
- Civil engineering: bridges, roads and infrastructure
- Building construction: commercial, cultural and educational facilities
- Construction technology and innovation
Notable projects
- Esplanade – Theatres on the Bay, Singapore
- Tamagawa Sky Bridge, Kanagawa and Tokyo, Japan
- New educational facilities for The Hong Kong Polytechnic University (contract awarded October 2026)


Overseas offices
Hong Kong, Vietnam, Indonesia, Malaysia, Thailand and Myanmar branch offices, and an Africa Regional Office
Contact details
পেন্টা-ওশান কনস্ট্রাকশন — জাপানের শীর্ষস্থানীয় সামুদ্রিক নির্মাণ, ড্রেজিং ও অবকাঠামো নির্মাণ প্রতিষ্ঠান (প্রতিষ্ঠা ১৮৯৬)।