India's markets regulator may impose penalty of up to 15 billion rupees ($328 million) on Reliance Industries if it establishes the energy major was involved in insider trading, the Economic Times reported on Monday, citing an unnamed source close to proceedings.

The penalty relates to a November 2007 sale of shares by Reliance in its then unit Reliance Petroleum, where it is alleged to have made a profit of 5 billion rupees from insider trading, the newspaper said.

Reliance had offered to settle the case twice through consent orders, but these have been rejected by the Securities and Exchange Board of India (SEBI) as the money Reliance offered to pay was too low, the paper said.

Officials at Reliance Industries and SEBI were not immediately available for comment.

The markets regulator can impose a penalty of up to three times the profit a company made from insider trading.