Houston Municipal Employees Pension System committed $25 million to Riverstone Global Energy and Power Fund VI, spokesman Peter Koops said in an e-mail.
The energy fund is managed by Riverstone Holdings.
In February 2012, the $2.5 billion pension fund committed up to $10 million to predecessor fund Riverstone Global Energy and Power Fund V.
The pension fund has a 17.5% target allocation to private equity.
