The deal, which is expected to close in the summer, will allow the buyers to acquire a further 3.33 percent in ABP, depending upon pre-emption rights, they said in a statement.

"This investment is an important addition to our global infrastructure portfolio and fits well with CPPIB's long-term investment mandate," said Cressida Hogg, managing director and global head of infrastructure at CPPIB.

Hermes Infrastructure, part of British-based fund Hermes Investment Management, and CPPIB will buy the ABP stake from GS Infrastructure Partners and Infracapital.

Borealis Infrastructure and Government of Singapore Investment Corp (GIC) will remain ABP shareholders.

Macquarie Capital and Deutsche Bank acted as advisors to CPPIB and Hermes.

($1 = 0.6775 pounds)

(The story was refiled to correct the headline to say stake in Associated British Ports, not the company)

(Reporting by Ankush Sharma in Bengaluru; Editing by Anupama Dwivedi)