Following an essentially flat first half of 2008, private commercial mortgages held by life insurance companies posted a negative 2.08 percent total return for third quarter of last year, according to the LifeComps Commercial Mortgage Index.

Of total return in the third quarter, 1.61 percent was income return and negative 3.69 percent was price return, the company said. The negative price return resulted from higher mortgage spreads and lower valuations which overrode the positive effect from lower treasury yields.

The LifeComps Commercial Mortgage Index is a benchmark for the private commercial mortgage market based on actual cash flow data, which has been collected quarterly from participating life insurance companies since 1996.