Wall St to open lower as Citi misses estimates

NEW YORK (Reuters) - Stocks were set for a lower open on Tuesday after Citigroup earnings missed estimates, while Apple shares weighed on the technology sector after Chief Executive Steve Jobs took another medical leave.

The S&P index futures gave up earlier gains and turned negative after No. 3 U.S. bank Citigroup Inc posted a $1.3 billion quarterly profit but missed estimates as revenue slumped. Citi fell 4.5 percent at $4.90 in premarket trading.

"Expectations for the financial group are high thanks to an improving economy and a generally better atmosphere," said Richard Sichel, chief investment officer at Philadelphia Trust Co. "(Citi's) numbers will be taken with some degree of skepticism as we look through to see how they got here. But obviously since they missed, that won't be rewarded in the market."

Investors have been hopeful of a strong earnings season, especially in the U.S. banking sector, after JPMorgan Chase & Co reported strong results last week. Financials have been among the market leaders in the recent rally. The S&P ended Friday with its seventh straight week of gains.

Apple Inc dropped 4.6 percent to $332.40 premarket after the company said Jobs is taking his third medical leave since 2004, reviving concerns about the future of the maker of the iPad and iPhone. Apple is due to report results later Tuesday.

S&P 500 futures fell 1.8 points and were below fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures gained 15 points, but Nasdaq 100 futures lost 18.75 points.

Investors also braced for results from International Business Machines Corp later in the day.

In corporate news, Goldman Sachs Group Inc will limit its private placement of shares of Facebook, the social networking site, to investors outside the United States, citing "intense media coverage."

U.S. President Barack Obama ordered a review of regulations in hopes of spurring economic growth and job creation, the White House said. In an op-ed piece in Tuesday editions of the Wall Street Journal, Obama said government regulations have placed "unreasonable burdens on business.

In the latest economic data, a gauge of manufacturing in New York State rose in January, but fell short of forecasts.

(Reporting by Angela Moon; editing by Jeffrey Benkoe)