SAN ANTONIO-The Teachers Retirement System of Texas has joined the US Government Building Fund LLC, a fund run by locally-based USAA Real Estate Co. The fund now has an equity commitment of $546 million, with total size expected to exceed $1 billion.

Sam Mitts, executive managing director at USAA, said he can’t comment on how much TRST has contributed to the fund. “We are oversubscribed,” he says.

The fund is designed to acquire office properties that are mostly leased to US federal and state government agencies. Currently, the fund has three properties worth $281 million, including buildings in Richmond and Sacramento, and the 430,000-square-foot FBI building at 2111 W. Roosevelt in Chicago. All three were purchased in the past 20 months.

However, Mitts tells GlobeSt.com that another purchase of more than $120 million will soon close. “We have another major asset under contract, it should happen the first part of October,” he says. The location of the building can’t be disclosed yet, Mitts says.

Nearly 1.3 million public education and higher education employees and retirees from Texas participate in the $88.7 billion TRST system. Pat Duncan, chairman and CEO with USAA, said TRST has invested with his company once before, and that it is good to have the system as a co-investment partner. “We have pooled our resources to generate a very large and significant portfolio,” Duncan said in a statement.