By Donna Kardos Yesalavich U.S. stocks opened broadly lower Tuesday, pushing the Dow Jones Industrial Average below the key 11,000 level as worries over euro-zone debt returned. The Dow (DJI) dropped 158 points, or 1.4%, to 10,994, in early trading. That wipes out Monday's gain of about 143 points. The measure's most economically sensitive components, which had led Monday's rally, reversed Tuesday to lead its declines. Alcoa (AA) fell 4%, Caterpillar dropped 3.4% and Walt Disney fell 2.2%. Just a few Dow components were in the black, led by Merck (MRK), which climbed 2.1%, and Pfizer (PFE), which climbed 1.5%. The companies reported declines in first-quarter profits as both drug makers incurred costs digesting large acquisitions and felt the early effects of the U.S. health-care overhaul. Both companies' sales and earnings excluding certain costs, however, exceeded Wall Street expectations. The Nasdaq Composite (RIXF) slipped 2.3%. The Standard & Poor's 500 (SPX) index declined 1.6%. All its sectors were in the red, led by industrials, which had several earnings disappointments. Among them, Pitney Bowes posted a 24% drop in first-quarter profit on lower sales. The mail and document-management company's earnings exceeded Wall Street's expectations, though revenue fell short. The stock declined 2.1%. Tuesday's broad declines in U.S. stocks came as the euro (CUR_EURUSD) fell to a 12-month low against the dollar on skepticism over the Greek government's ability to carry out harsh austerity measures required by its aid package. Although the German government negotiated to provide the lion's share of the European Union contribution to Greece, there is little assurance that Chancellor Angela Merkel will get the electoral backing for the bailout. Not helping, data from Germany showed retail sales fell 2.4% in March. The U.S. Dollar Index (DXY), reflecting the U.S. currency against a basket of six other currencies, jumped 1%. Treasurys rose, pushing the yield on the 10-year note down to 3.61%. Crude-oil futures fell below $84 a barrel while gold futures edged higher. Among stocks in focus, Apple (AAPL) shares fell 1.9%. U.S. antitrust enforcers are taking a keen interest in recent changes that the company made to its licensing agreement with iPhone application developers and are likely to open a preliminary investigation into whether the company's actions stifle competition in mobile devices, The Wall Street Journal reported, citing people familiar with the situation. Interactive Data (IDC) rose 0.7% after the company reached a deal to be purchased by private-equity groups Silver Lake Partners and Warburg Pincus for $3.4 billion. Majority owner Pearson (PSO) will receive $2 billion before tax from the deal. Its shares slid 4.5%. Still to come, data on pending home sales and factory orders are due at 10 a.m. EDT.