OREANDA-NEWS. National Rating Agency (NRA) has withdrawn its credit rating on Pluton OJSC due to expiry of the contract. The company has been assigned an exit rating of ‘A-’. Pluton OJSC got NRA’s first-time credit rating of ‘A+’ on July 10, 2014. The latest rating action on the company (the credit rating downgrade to ‘A’ with a stable outlook) was on Aug. 31, 2015.