Hess said that ONGC's foreign investment arm ONGC Videsh
Hess said the sale was part of an asset sale program under which it is trimming mature assets, as well as stakes in projects in which it only holds a small working interest. It said it has announce nearly $2 billion in sales this year.
The BP-operated ACG oilfields are in the Caspian Sea around 100 kilometers east of Baku.
ACG accounts for the lion's share of Azeri production and is the main source of crude for a pipeline which runs via Georgia to the Mediterranean port of Ceyhan in Turkey.
In August, The BP-led
Local officials attributed the output fall at the project, which has total reserves of over 6.5 billion barrels, to repair work on some drilling platforms and refineries.
The country expects its oil output to rise in 2013 thanks to the start of the next stage in ACG's development.
Rothschild advised ONGC Videsh on the sale.