PASADENA, CA-Morgan Stanley Real Estate Investing and Lincoln Property Co. have acquired the 950,000-square-foot headquarters campus of engineering firm Parsons Corp. in an off-market transaction that is the largest single office property sale in L.A. County since 2007 and a sign of rapidly increasing office sales volume in the county. Terms of the sale were undisclosed, but sources not involved in the transaction say that the buyers paid $320 million for the Parsons property, which the engineering firm has leased back for 15 years.

Vice chairman Kevin Shannon of CB Richard Ellis, who represented the buyers, tells GlobeSt.com that the deal was the largest office sale in L.A. County since the $327 million sale of the AON Center in Downtown Los Angeles in 2007. The Parsons sale is also believed to be the largest office sale this year in the Western US, Shannon says. He points out that the Parsons deal is part of a larger trend in which office sales volume for the first six months of this year in Los Angeles County has already slightly exceeded the total for all of 2010. The total for 2010 was $1.531 billion, and the total for the first six months of this year, including the Parsons sale, is $1.538 billion.

“We bottomed out in ‘09, and then velocity picked up last year,” Shannon said. “This year, we are getting closer to 2005 levels. There is clearly more optimism and more capital out there.”