DUBAI, Sept 25 (Reuters) - State oil giant Abu Dhabi National Oil Company (ADNOC) and Abu Dhabi National Energy Company (TAQA) said on Monday they secured the financing for a $2.2 billion project to provide sustainable water supply to ADNOC's onshore operations.

The project, which was announced in May, will comprise a centralised seawater treatment facility for ADNOC's operations at the Bab and Bu Hasa fields in Abu Dhabi, as part of the oil giant's efforts to decarbonize its business.

A group of nine local banks and international banks will finance the project, through a combination of commercial and Islamic finance facilities, ADNOC and TAQA said in a bourse statement.

The banks to finance the project are First Abu Dhabi Bank, Gulf International Bank, Natixis, Abu Dhabi Commercial Bank, Abu Dhabi Islamic Bank, Commercial Bank of Dubai, Emirates NBD, Emirates Development Bank and Warba Bank.

A consortium comprising Orascom Construction and Metito will construct a seawater treatment facility and transportation and distribution network.

ADNOC and TAQA each own a 25.5% stake in the project, resulting in a combined 51% majority, while the consortium will own the remainder under a build, own, operate and transfer model.

(Reporting by Hadeel Al Sayegh; Editing by Sherry Jacob-Phillips)