Wall Street facing rough session

LONDON (CNNMoney.com) -- Wall Street braced for a tough day after Citigroup Inc. reported a nearly $10 billion loss in fourth-quarter earnings.

The financial giant Citigroup (C, Fortune 500) reported an $18 billion writedown as part of a restructuring plan and slashed its dividend.

U.S. stock futures were lower, showing investor skepticism, before Citi reported earnings and didn't move much after the bank's report.

Citi is the first of many financial services firms to report quarterly earnings this week. JP Morgan Chase (JPM, Fortune 500) is due to report Tuesday and Merrill Lynch (MER, Fortune 500) is slated to post results Thursday.

Also on Tuesday, Merrill said it signed a deal to raise $6.6 billion in preferred stock from long-term investors the Korean Investment Corp., Kuwait Investment Authority and Mizuho Corporate Bank.

Retailers are also likely to be in focus with the government's report on December retail sales on tap.

Other stocks to watch include Genentech (DNA), which reported quarterly sales that disappointed Wall Street late Wednesday.

Sprint (S, Fortune 500) plans to cut several thousand jobs under new CEO Dan Hesse, according to a report in the Wall Street Journal.

On the tech front, Apple (AAPL, Fortune 500) CEO Steve Jobs is due to deliver his keynote address at Macworld, Silicon Valley's largest tech show. In the past, Jobs has used the speech to announce new Apple products like the iPhone.

In global trade, Asian markets tumbled, and European stocks dipped in morning trading.