Canada's Borealis Infrastructure is in the early stages of launching a takeover bid for British utility firm Severn Trent.
The investment vehicle previously bid for the FTSE 100 water company in May 2013, as part of the LongRiver Partners consortium which also included the Kuwait Investment Office and UK pension fund the Universities Superannuation Scheme.
The consortium made multiple offers, with the final approach valuing the firm at around £5.2bn.
Severn Trent rejected that offer, stating at the time that it had "concluded that [the bid] completely fails to recognise the existing and potential value" of the company. LongRiver Partners then walked away from the deal.
The group later revealed that it had incurred £19m in advisory and legal costs after rejecting the offer.
News of the latest approach was first reported by the Sunday Times.
The water company revealed last month that it suffered a 53.5 per cent drop in pre-tax profits in the year to the end of March 2015, from £318.9m in 2014 to £148.2m. The firm attributed this decline largely to a one-off charge for currency and interest rate swaps.
Severn Trent declined to comment yesterday.