National oil companies - ONGC Videsh, Oil India, Indian Oil Corporation and Bharat PetroResources - and Russia's Rosneft may sign memorandums of understanding and agreements on Wednesday to increase India's participation in the Siberian oil and gas fields. A final round of talks between the Indian companies and Rosneft took place on Tuesday that was also attended by Rosneft's Chief Executive Igor Sechin who is visiting India. Indianmandarins has learnt that ONGC Videsh, the overseas investment arm of ONGC, may sign an MoU to raise its stake in the Vankor field in Siberia from the current 15 per cent. Another MoU may see IndianOil, Oil India and Bharat PetroResources pick up a stake in the same Vankor field. All of this may raise India's stake in the field to 49.9 per cent. A sale purchase agreement may also be signed between Rosneft and IndianOil, Oil India and Bharat PetroResources to give the Indian companies a 29 per cent stake in the Taas-Yurikah fields in Eastern Siberia. An MoU was signed between IndianOil, Oil India and Rosneft in this regard inRussia last December. The sale purchase agreement could also see Bharat PetroResources join the deal.