UBS AG boosted its earnings estimates for the Standard & Poor’s 500 Index this year and next, citing a better outlook for the world’s largest economy.

Earnings for companies in the equity benchmark will amount to $96 a share this year and $104 a share next year, the Zurich-based firm said in a note today, revising its projections from $93 and $101, respectively. UBS held the 2010 estimate at $86 per share.

The S&P 500 climbed 6.5 percent last month, the biggest December rally since 1991, as reports on jobs, retail sales and manufacturing were better than estimated, prompting economists to raise their projections for 2011 U.S. domestic product growth by 0.2 percentage points since November. Commodities also increased, propelling the Thomson Reuters/Jefferies CRB Index of 19 raw materials to its best month since May 2009.

“Since we last raised our estimates in early November, the macro backdrop has improved,” a group of strategists, led by New York-based Thomas Doerflinger, wrote in the report. “We remain bullish on U.S. profits.”