By Carolyn Cohn and Simon Jessop LONDON (Reuters) -Asset managers including France’s Amundi and BNP Paribas, Britain’s HSBC and Switzerland’s Pictet have frozen Russia-focused equity funds totalling over $3 billion in assets, as markets seize up following sanctions on Russia. Russian assets have gone into freefall due to the crippling restrictions, and Moscow has placed temporary curbs on foreigners seeking to exit them. Asset managers typically only suspend funds in exceptional circumstances, including when assets are hard to value, in order to ensure investors are treated equally. Pictet sai…