The North Carolina pension system, which is facing scrutiny over past investment practices, posted a gain of 12.28 percent in 2013, with equities more than doubling that rate of return.

State Treasurer Janet Cowell, who is one of the few public pension administrators empowered to act as sole fiduciary, reported that the fund ended last year with $86 billion in assets, a rise of $8 billion for the year. Stock gains were 26.24 percent for the year.

Other parts of the portfolio performed well, too, with credit up 7.6 percent, real estate 11.56 percent and private equity gaining 11.72. Fixed income bonds had a loss of 3.49 percent.

The fund is the 11^th largest public retirement system in the country and covers 875,000 employees and retirees, including teachers, state workers, firefighter and police officers.

In a recent interview, Cowell said that although she had sole power to make investments in the fund, the General Assembly provided a check and balance to the process. Still, she has appointed a commission to consider how the pension system is run and whether the lines of authority should be changed.

The state employees union, SEIU Local 2008, last month hired Benchmark Financial Services Inc. to look into the fund’s investments and whether it paid exorbitant fees. Benchmark said any violations it finds as a result of its forensic audit would be forwarded to the Securities and Exchange Commission.

In general, the North Carolina pension fund is well funded. A Pew Charitable Trusts report in 2012 found the system was 96 percent funded.