Investors next week will try to maintain upward stock market momentum achieved via three consecutive positive sessions.

Robust corporate earnings and some positive labor market data fueled the rally. The gains were made despite the devastation in Japan, rising oil prices sparked by continued unrest in the Middle East and a decline in consumer sentiment brought on by soaring costs at the gas pump and the grocery store.

Key releases next week, according to IHS Global Insight, include the March employment report on Friday, which is expected to show payroll employment rising by 160,000, and the unemployment rate staying the same at 8.9%.

Stubbornly-high unemployment is widely viewed as the biggest roadblock to a full recovery from the recent recession.

February real consumer spending, to be released Monday, and construction spending, out on Friday, are expected to show gains from January when bad weather in much of country cut into spending in those sectors.

The Institute for Supply Management’s Manufacturing Index, also out of Friday, is expected to hit its highest level in 28 years, according to IHS Global.

Manufacturing has been a consistent positive as the U.S. has struggled to dig out from the economic downturn.

Auto sales, also out on Friday, likely fell in March from the previous month, as did consumer confidence as measured by the Conference Board’s consumer confidence index, out on Tuesday.

“Auto companies are seen to have eased incentive programs due to lean inventories and concerns over parts shortages emanating from the disruptions in Japan following the earthquake and tsunami,” IHS Global said in a report to clients.

Also on tap next week is a full slate of initial public offerings, reports Renaissance Capital, a Greenwich, Ct.-based IPO research firm.

Apollo Global Management, a New York-based money management firm, is set to raise $473 million through the sale of more than 26 million shares at a projected range of $17 to $19. Goldman Sachs (NYSE: GS) , JPMorgan (JPM) and Bank of America Merrill Lynch (BAC) are managing the deal.

GNC Holdings Inc., a Pittsburgh-based retailer of health products, is set to raise $360 million through the sale of 22.5 million shares at a projected range of $15 to $17. Goldman Sachs, JPMorgan and Deutsche Bank Securities (NYSE: DB) are managing the deal.

Preferred Apartment Communities, an Atlanta-based real estate investment trust, is set to raise $45 million through the sale of 4.5 million shares at $45. Wunderlich Securities is managing the deal.

Qihoo 360 Technology, a China-based Internet security firm, is set to raise $139 million through the sale of more than 12 million shares at a projected range of $10.50 to $12.50. UBS Investment Bank (NYSE: UBS) is managing the deal.

Tranzyme, a Durham, N.C.,-based drug company, is set to raise $60 million through the sale of 5 million shares at a projected range of $11 to $13. Citigroup (NYSE: C) is managing the deal.

Renaissance Capital said 28 IPOs have priced so far in 2011, a 17% increase over the same period a year ago. A strong IPO calendar is viewed as a positive sign for the broader economy.

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