The California Public Employees’ Retirement System is looking for an asset manager to oversee a separately managed account that the country's largest pension fund would use to focus on infrastructure investment, a sector that has done very well for the fund lately.

CalPERS would commit as much as $1.5B to the fund, Bloomberg reports, citing anonymous sources.

The Sacramento, California-based CalPERS counts infrastructure as a category of real assets, along with real estate and forestry investments. CalPERS — with assets totaling about $350B — has $4.1B allocated to infrastructure.

The pension fund has done well in infrastructure, which has delivered a five-year realized net return of 14.3%, besting various other investments in private equity and equities over the same period.

The separately managed account structure is increasingly popular among pension funds, since it allows lower costs and more control over investments. That is an important consideration in infrastructure, since investments in the sector tend to be for longer periods.

Last year, New York City's pension system struck a $3B separately managed acccount deal with KKR & Co. to invest in private equity, infrastructure, real estate and credit investments.

Infrastructure investment has received attention recently, with the Trump administration proposing $200B in federal spending over 10 years for bridges, roads and public works. That, in turn, would be designed to spur $1.5 trillion in investments for U.S. infrastructure.