The lifeboat fund said any selected provider would need to operate globally and advise on all existing public equity and fixed income benchmarks, including those for emerging market debt.
It also said any company able to provide ESG data and research for private equity and private credit markets would be viewed favourably.
The PPF last year said it was considering a move into direct lending, and it has been active in the private equity market for a number of years.
The tender said the PPF intended to “widen the scope” of its responsible investment (RI) policies to include other ESG factors in future.
Since 2012, the fund has included clauses in its contracts with asset managers outlining expectations in terms of RI.
It also uses a traffic-light system to rate managers based on five RI criteria, including stewardship, and regularly discloses how Hermes Equity Ownership Services votes on its behalf.
The two-year initial contract could be renewed up to three times, with all proposals due by 21 August.