Stocks in the news: Coca-Cola, Merck, Caterpillar, General Motors

Merck & Co. (MRK) on Tuesday posted a 57 percent drop in first-quarter profit, recording earnings per share of 74 cents excluding items and falling short of expectations of 77 cents a share. The company blamed drop in sales of its drugs and loss of income from its partnership on cholesterol medicines. MRK opened down over 7 percent.

Coca-Cola Co. (KO) said its first-quarter profit fell 10 percent on restructuring charges and write-downs but the results met analysts' estimates despite the challenging economic environment. Coca-Cola's net income excluding items was $1.51 billion, or 65 cents per share, which met the expectations of analysts polled by Thomson Reuters. KO shares were a little higher in the first minutes of trade.