Goldman Sachs ( GS) watchers are looking once again for a big contribution from the bank's various trading businesses to drive second-quarter profits when the bank reports on Tuesday.

Goldman is expected to earn more than $1.7 billion, or $3.47 a share, according to consensus estimates of 16 analysts surveyed by Thomson Reuters . The company earned $4.58 a share in the year-ago quarter.

"The spreads remain wide and volatility is high," wrote Dick Bove, an analyst at Rochdale Securities.

Several analysts also cited reduced competition as a continued benefit for Goldman, as the credit crisis drove Lehman Brothers out of business and Bear Stearns and Merrill Lynch into the arms of JPMorgan Chase ( JPM) and Bank of America ( BAC), respectively.

Even some noted bears are bullish on Goldman. The stock rallied as much as 5.6% on Monday after analyst Meredith Whitney, head of Meredith Whitney Advisory Group, published a report arguing Goldman will benefit from a massive surge in debt issuance as government and corporate entities try to plug funding gaps.

"In the past, Goldman shares were a great play on equity markets and expansive global GDP. While that may still hold true down the line, our thesis today is that we expect Goldman to be the key competitor in some of the most unpredictable markets: government, corporate, and municipal debt," Whitney wrote. Her price target of $186 is more than 30% higher than where Goldman's shares closed on Friday. Research firm Institution Risk Analytics also upgraded Goldman on Monday.

Equity underwriting is expected to be another big contributor to Goldman's second-quarter numbers, principally from financial companies raising equity to shore up their balance sheets or pay back government equity infusions. Credit Suisse analyst Howard Chen expects a gain of 879% in this unit for Goldman compared to the second quarter of 2008.

Goldman was one of several institutions that repaid U.S. government preferred equity stakes bought through the Troubled Asset Relief Program. This increases costs to Goldman in 2009, but will improve profitability in 2010 and 2011, analysts write. Morgan Stanley ( MS), Capital One Financial ( COF), US Bancorp ( USB) and American Express ( AXP) are among other financial companies that have repaid TARP. JMP Securities' analyst Michael Hecht estimates the $10 billion TARP payback will knock 79 cents off of Goldman's second quarter numbers.

On the downside for Goldman, several analysts are looking for continued losses in its commercial real estate holdings through its proprietary private equity arm. Hecht forecasts as much as $1.5 billion of commercial real estate-related writedowns, while Credit Suisse's Chen is calling for a more modest $600 million in losses in this area.

Goldman's balance sheet is widely seen as strong, with the firm having set aside a large capital cushion in the wake of the crisis. UBS analyst Glenn Schorr believes Goldman will eventually put some of this capital to a more profitable use, possibly in the form of share buybacks. Such buybacks drove big returns for Goldman shareholders between 2004 and 2007, Schorr writes, though he has questions about how liberal regulators will be in allowing Goldman to subject its balance sheet to additional risks.