Chrysaor is focused on the development and commercialisation of dormant oil and gas discoveries and incremental reserves in Europe.
The firm is owned by a combination of the current management team, Barclays Natural Resource Investments (a division of Barclays Capital), and a fund managed by Natural Gas Partners.
The agency will provide strategic comms advice covering media relations and UK and European public policy. The account will be headed by Ken Cronin, managing partner in London, and partner Kate Hill.
Cronin said: 'Chrysaor is a young company managed by industry veterans with an enviable track record of investing and operating in the sector.'