Magna plans to bid for small and medium sized fields which are to be auctioned by the government later this fiscal as also in future exploration licensing rounds, he told PTI. US-based private equity firm Carlyle Group on Monday said it will invest $500 million in Magna Energy Ltd, an India-focused oil firm founded by Mike Watts, the man who saw oil in Rajasthan's Thar desert where global giant Royal Dutch Shell saw none.