US Stocks are edging higher in midday trading as investors consider the latest news on corporate mergers. According to AP, Abbott Laboratories rose 2 percent after financial analysts cheered the medical device maker's proposed acquisition of CFR Pharmaceuticals for nearly $3 billion. Pfizer rose 1 percent after AstraZeneca's board rejected Pfizer's latest takeover offer. AstraZeneca sank 10 percent. The Dow Jones industrial average rose 25 points, or 0.2 percent, to 16,516 in midday trading Monday. The Standard & Poor's 500 index rose five points, or 0.3 percent, to 1,883 and the Nasdaq composite rose 32 points, or 0.8 percent, to 4,123. AT&T fell 1 percent after the company said it plans to buy satellite TV provider DirecTV for $48.5 billion. The proposal could face tough regulatory scrutiny. DirecTV also fell 1 percent.