Goldman Sachs weighed in on a couple of its investment-banking peers this morning, with the brokerage firm recommending a pairs trade on Morgan Stanley (MS: sentiment, chart, options) and Citigroup (C: sentiment, chart, options) . Analyst William Tanona is bullish on Morgan Stanley, noting that it has the best product mix to weather a downturn in the market. The analyst has a "buy" rating on MS, and maintains a price target of $50 -- a 31% premium to the stock's closing price Tuesday.

Tanona also recommends shorting Citigroup, due to its heavy exposure to the mortgage and consumer-credit markets. His price target on C is $16, a discount of 7% to the shares' closing price yesterday.

Despite his bullish note on Morgan Stanley, Tanona believes we're "still a few quarters away" from a recovery in the financial sector. He noted that most investment banks will have either flat or negative earnings in the third quarter, extending a lengthy losing streak for the group.

The market appears to be taking the MS note with a grain of salt, as those shares are 1.7% lower this morning. Meanwhile, C has declined by about 1%.