YAHOO [BRIEFING.COM]: Concerted selling sent the S&P 500 and the Nasdaq Composite to their worst single-session losses in almost two months, but the Dow finished only fractionally lower amid support from IBM.

Surprisingly strong earnings propelled shares of IBM (IBM 155.69, +5.04) to their best level on record. The 3% surge propped up the price-weighted Dow Jones Industrial Average for the entire session.

However, action in the S&P 500 and Nasdaq Composite was governed by aggressive selling.

The broad-based S&P 500 saw about 86% of its components close lower. Financials were among the hardest hit; they sank to a 2.2% loss. Marquee investment bank Goldman Sachs (GS 166.49, -8.19) posted better-than-expected earnings, but those were overshadowed by a smaller-than-expected revenue figure. The stock suffered its worst single-session loss in more than eight months and closed below its 50-day moving average.

Northern Trust (NTRS 52.49, -3.15) dropped to a one-month low after its earnings fell short of what had been expected. State Street (STT 48.00, -2.06) also slid, even though its exceeded earnings expectations. Diversified banks Wells Fargo (WFC 31.81, -0.68) and US Bancorp (USB 26.52, -0.79) were caught up in the financial sector's slide, regardless of generally solid reports.

Apple (AAPL 338.84, -1.81) had another blowout quarter and even issued a strong forecast. Given that the firm's forecasts are typically tepid, many wonder whether or not the outlook was intended to offset discontent over yesterday's news that Apple CEO Steve Jobs will take another medical leave of absence. Support for shares of AAPL faded so that the stock settled in the red with several other large-cap tech issues, which were the heaviest drags on the Nasdaq.

Defensive-oriented plays made up the only major sectors that suffered losses of less than 1%. Telecom and utilities were the best performers; they slipped only 0.1%.

Only a small dose of data was released this morning. It did nothing to drive broader market action. According to the latest data, housing starts for December fell 4.3% month over month to an annualized rate of 529,000, which is below the rate of 550,000 that had been expected, on average, among economists polled by Briefing.com. The December sales rate is also the lowest since October 2009. As for building permits, they spiked 16.7% month over month to an annualized rate of 635,000, which is well above the rate of 560,000 that had been widely expected. The December building permit rate is the highest since March 2010.

The dollar succumbed to further selling today. Its 0.5% loss marked its seventh downturn in eight sessions. The Dollar Index now sits near a two-month low.

Commodities finished mixed on the session, with grains (-0.8%) the largest decliner and energy and industrials (+0.6%) the largest advancers.

Feb natural gas futures closed higher by 2.7% to $4.55 per MMBtu, and were the largest advancing future in the energy complex. Cold weather helped support prices. Feb crude oil shed 0.6% to settle at $90.86 per barrel.

Despite weakness in the dollar, neither gold or silver was able to finish with any substantial gains. Feb gold ended higher by 0.1% to $1370.20 per ounce, while March silver shed 0.1% to finish at $28.80 per ounce. Both metals have extended their pullbacks in electronic trade.

Advancing Sectors: (None)
Declining Sectors: Materials (-2.2%), Financials (-2.2%), Industrials (-1.0%), Consumer Discretionary (-1.0%), Energy (-1.0%), Tech (-0.7%), Health Care (-0.6%), Consumer Staples (-0.3%), Telecom (-0.1%), Utilities (-0.1%)DJ30 -12.64 NASDAQ -40.49 NQ100 -1.1% R2K -2.6% SP400 -1.7% SP500 -13.10 NASDAQ Adv/Vol/Dec 460/2.18 bln/2218 NYSE Adv/Vol/Dec 673/1.08 bln/2319