State Universities Retirement System (SURS) of Illinois and Maine Public Employees Retirement System (Maine PERS) are both investing in North American infrastructure funds.
SURS told IPE Real Estate it had approved a $50m (€44.8m) commitment to Macquarie Infrastructure Partners IV.
Macquarie Infrastructure and Real Assets, which did not comment, is understood to be targeting $3.5bn for the fund, which will invest mostly in the US and Canada.
Earlier this year, New Mexico State Investment Council committed $100m to the fund.
Macquarie is aiming to buy seven to 10 large, existing and late-stage development infrastructure assets.
It will focus on utilities and energy, transportation, communications and waste management.
The fund is intended to produce a net internal rate of return (IRR) of 10% to 12% and will use approximately 50%.
SURS has invested in previous funds in the series. it holds investments valued at $32m in Partners II and $37m in Partners III.
Maine PERS, meanwhile, said it approved a $50m commitment to the Meridiam Infrastructure North America Fund III.
Meridiam, which did not comment, will also focus on the US and Canadian markets.
Its strategy is to provide equity for projects sponsored by public authorities for the benefit of local communities.
It focuses on transport, social infrastructure, public buildings, utility networks and services such as water and waste management.
Maine PERS has invested with Meridiam in the past, including commitments to previous funds.