Thomas Properties Group and the California State Teachers’ Retirement System on Wednesday announced that their new joint venture has bought out partners in eight office buildings in Austin, Texas to gain full ownership of the properties.

The Los Angeles a real estate investment trust said that the joint venture, called TPG/Calstrs Austin LLC, paid $859 million to Lehman Brothers Holdings Inc. and another syndication partner for the office buildings and assumed five mortgage loans totaling $626 million. Thomas Properties acquired the portfolio with Lehman Brothers in 2007.

The deal reduced about $200 million of debt on the portfolio by paying an amount owed to Lehman Commercial Paper Inc., said Thomas Properties, which is the managing partner in the 50/50 Calstrs joint venture.

Chief Executive James Thomas said the buildings in downtown and suburban Austin are “crown jewels” in that market. “We are very encouraged by the continued strength in the Austin market and the prospects for future growth,” he said in a statement.

Thomas shares closed down 14 cents, or 2.4 percent, to $5.79 on the Nasdaq.