The 14-year loan is to help finance construction of a port complex in the southeastern city of Al-Duqm.
The plans, which include dry docks alongside the port, are expected to require investment of around $1.1 billion.
Reports say the port is scheduled to be operational by 2009, while the ship repair yard is to be completed by 2010.
Oman government officials want the port to develop into a major industrial and commercial hub with power generation, petrochemical production and water desalination plants.