Another batch of earnings announcements sent shares lower, as weak results from non-financial firms fueled investor concerns that economic weakness is spreading to other industries.

At midday in New York, the blue-chip Dow Jones Industrial Average Index was down 76.86 points (-0.60%), to trade at 12,748.16. The tech-laden Nasdaq Composite Index shed 17.41 points (-0.72%), to reach 2,390.63. And the broader Standard & Poor’s 500 Index decreased 8.41 points (-0.61%), to hit 1,379.76.

Most sectors were down, with the energy sector (up 0.43%) and the basic materials sector (up 0.08%) posting the only gains. The consumer cyclical sector (down 1.75%) and the technology sector (down 1.12%) had the largest declines.

“Earnings and earnings estimates are coming down,” Mike Ryan, the New York-based head of wealth management research for the Americas at UBS Financial Services Inc., which oversees about $734 billion, said in an interview on Bloomberg Television. “We’re likely to see stocks continuing to be under pressure” in the first half of 2008.

Despite a 24% increase in profit, McDonald’s Corp. (MCD) slumped after it announced a slight decrease in same-store sales for March.

Shares of UnitedHealth Group Inc. (UNH) and Texas Instruments Inc. (TXN) were also down sharply after announcing first quarter results.

In overseas markets earlier today, Japan’s Nikkei 225 Index lost 1.1% with a decrease of 148.73 points to close at 13,547.82. Hong Kong’s blue-chip Hang Seng Index gained almost 1% with a 217.48-point climb, to 24,939.15.

European bourses were down, with the Paris-based CAC40, London’s FTSE 100, Madrid’s IBEX 35 and the Frankfurt-based DAX all posting losses.

At midday, the dollar had lost ground against the euro (down 0.457%) and the pound sterling (down 0.812%), but gained ground against the yen (up 0.204%).