LONDON (Reuters) -British insurer and asset manager M&G has only 0.1% of its assets under management exposed to Russia, and will divest of those assets when it can, CEO John Foley said on Tuesday. The firm’s Russian assets have been marked almost to zero, and Foley said the asset manager had no plans to buy more. “Russia is an uninvestable market from a ratings perspective, any additional investment is clearly unthinkable,” he said. M&G joins a raft of asset managers who have said they will not buy more Russian securities and plan to sell what they have. But efforts by investors to cut positio…