Six banking groups pitched for the financial advisory mandate on the $25bn scheme in late April, with an award expected by the end of May. The fact that they have now been whittled down to two groups indicates that the time-scale for making an award is on track.

Aramco and Dow had originally drawn up a shortlist of six international banks and seven local banks, who were expected to partner-up and bid for the role.

The banking groups are HSBC with SABB, Calyon with Banque Saudi Fransi, Royal Bank of Scotland with Riyad Bank, BNP Paribas with Samba, Societe Generale with Gulf International Bank, and Citigroup with Apicorp (MEED 2:5:08).