The Security and Exchanges Board of India on Friday barred Mukesh Ambani’s Reliance Industries Limited from trading in the equity derivative market for a year after finding it guilty of using “fraudulent and manipulative strategy” to make “unlawful gains of Rs 513 crore”. The case dates back to 2008 and involves the now defunct Reliance Petroleum Limited.

Reliance, the second most valuable firm in the country, will now have to pay a penalty of Rs 447.27 crore with 12% interest from November 2007, which amounts to nearly Rs 1,300 crore, The Indian Express reported.

RIL has said it will appeal against the order, which it needs to comply with in 45 days. The order names 12 others in the case, saying they carried out a “fraudulent scheme” with the intention of “making profits on account of the legally impermissible limits held by it clandestinely and lowering the price in the cash market”.

Sebi had in 2008 accused Reliance of violating norms saying it merged its petroleum arm into itself the previous year by allegedly short-selling a 4.1% stake in RPL in the futures market and then the spot market. However, Reliance maintains that the trades were carried out “keeping the best interest of the company and its shareholders, in view” and that Sebi had “misconstrued the true nature of the transactions and imposed unjustifiable sanctions.” The company will appeal against the decision in the Securities Appellate Tribunal.