Saudi Aramco and the US Dow Chemical are planning for banks to sign commitment letters for the commercial tranche of their $20bn Sadara Chemical project on 21 December, according to sources close to the project.

If the signing takes place before the end of the year as planned, it will open the way for focus to shift to the sukuk (Islamic bond) of about $2bn that is expected to be launched in the new year. The two sponsors behind the project confirmed pricing with lenders on the deal in early December.

The scheme is one of the largest project financings in the region and relies heavily on non-bank sources of financing, including Saudi government agencies, international export credit agencies and the local sukuk market.