Concept will be handling advertising across all media, public relations management and extensive on-ground activities including roadshows and conferences for the IPOs in India and abroad.

Commenting on this development Concept Communication MD Vivek Suchanti, said, "We are extremely pleased to get these prestigious accounts, as it underlines our ability to successfully manage large IPOs. Book Building issues require intensive promotion during a very small window period and we have specialised skills for the same. Our deliverables on the Maruti IPO have been appreciated and these assignments reaffirm the confidence of our clients."

ONGC public issue is of government’s 10 per cent stake. The 142 million equity shares will be offered in lots of 10 with a view to attract retail investors, for whom 25 per cent of the offer size has been reserved. ONGC offer for sale is approximately of Rs 105 billion, which makes it the biggest in the Indian capital market history.

DCI offer will constitute 20 per cent of the fully diluted post-offer paid up capital of the company. The offer is being made through the book building process, 50 per cent of the offer shall be offered on discretionary basis to qualified institutional buyers.