Octopus secures up to $600m from investment fund set up by Al Gore

Value of UK energy firm, which has taken on customers from collapsed rivals, put at $4.6bn

Octopus Energy, which has been taking on customers from collapsed rival suppliers, has secured up to $600m (438m) from an investment fund set up by the former US vice-president Al Gore.

Generation Investment Management (GIM), a $36bn fund manager that finances businesses focused on sustainability and tackling climate change, will take a stake of up to 13% in a deal that values Octopus at $4.6bn.