The Canada Pension Plan Investment Board (CPPIB) and Hermes Infrastructure are prepared to buy a 30 percent stake in Associated British Ports for about 1.6 billion pounds ($2.4 billion). Associated British Ports is Britain's leading port operator, with 21 ports in England, Scotland and Wales. The deal will allow the Hermes-CPPIB consortium to acquire a further 3.33 percent in the company, depending upon pre-emption rights, the buyers said in a statement on Tuesday. Infrastructure assets are attractive to institutions like pension funds because of the long-term investment opportunity and stable returns that they represent. Hermes Infrastructure, part of British-based fund Hermes Investment Management, and CPPIB will buy the stake from GS Infrastructure Partners and Infracapital.