Moody's Investors Service assigned triple-A ratings to most of $876.5 million of commercial mortgage-backed securities being sold by Goldman Sachs ($97.53 0%) and Citigroup ($26.92 0%).

Analysts said there are 43 fixed-rate loans secured by 108 properties in the nine classes of pass-trough certificates marketed through the GS Mortgage Securities Trust 2010-C2. Moody's rates $848 million of the bonds, as there is an unrated class, which is standard in conduit/fusion deals.

Some $347 million of Class A-1 and $376.1 million of Class A-2 certificates will carry gilt-edged ratings. Five other classes received ratings from Aa2 to B2, according to analysts.  The transaction is expected to close this month.

Moody's said the strong ratings reflect investment-grade credit estimates on six loans included in the transaction that account for about 16.1% of the pool balance.

Analysts said the loan level diversity of the transaction is strong, and "higher than the indices calculated in most multi-borrower transactions issued since 2009." More than one-quarter of the loans are secured by multiple properties, which lowers cash-flow volatility and further strengthens the credit, according to Moody's. Property-level diversity also helps the ratings. And while the pool balance has a high concentration of single-tenant properties, it's not enough to offset other strengths.

Nearly half of the loan pool includes retail properties that historically experience low volatility in operating income, while about 43% of the loans are office properties, which often experience high volatility in operating income levels and are riskier property types, according to analysts.

Wells Fargo ($31.67 0%) is master servicer for the transaction, and Midland Loan Services is special servicer.

Earlier this week, State Street ($30.06 0%) announced the sale of $11 billion of asset-backed securities, including $6.6 billion of MBS. The buyer wasn't disclosed, but Bloomberg reported Goldman Sachs was set to begin offering $6 billion of mortgages it acquired from the Boston-based institutional investor.

Write to Jason Philyaw.