The merger of the two banks will create the second largest commercial bank, in which HSBC owned 51% stake, while the remaining share will remain with OIB.
With the commencement of operations, the bank will elect a seven member board with four nominees from HSBC, to streamline its operations, said the bank.
According to HSBC, the absolute integration of the operations and re-branding is expected to complete by the end of this year.
OIB and HSBC branches will operate under the brand name of HSBC Bank Oman and will feature the HSBC red hexagon logo.
Under the terms of the deal, the HSBC Group will cater certain support services for a period of ten years to HSBC Bank Oman.
HSBC Bank Oman has named Simon Cooper as its chairman, who was serving as chief executive of HSBC Middle East and North Africa, while Ewan Stirling has been appointed as chief executive.
