Wall Street Opens Week With Losses

Elsewhere, Apple (AAPL Quote) added 2.1% on an upgrade to buy at AmTech Research. In more analyst calls, Stifel Nicolaus brought Google's (GOOG Quote) price target up $65 to $675, after which the search giant's shares climbed 2.3%.

Lehman Brothers shaved down Nortel's (NT Quote) price target, pressuring the stock by 2.2%, but lifted its price targets on mining-equipment makers Joy Global (JOYG Quote) and Bucyrus International (BUCY Quote). Shares advanced 2.2% and 3.8%, respectively.

On the data side, the Institute for Supply Management said its April nonmanufacturing index came in at 52, indicating expansion -- albeit slight -- for the first time in four months. Improved employment, among other things, buoyed the reading, which has a break-even point of 50. Economists were projecting slight contraction to 49.1.

Treasury prices were little changed. The 10-year note rose 3/32 in price to yield 3.85%, and the 30-year bond slipped 3/32 in price, yielding 4.58%.

Markets abroad were mixed. Hong Kong's Hang Seng Index slipped 0.2%. In Europe, Germany's Xetra Dax was up 0.1%, and the Paris Cac dipped by roughly that same amount. Tokyo's Nikkei 225 and London's FTSE 100 were each closed for a public holiday.