U.S. tax dispute

Lockheed Martin Corp. (NYSE: LMT) reported an 80% drop in second-quarter profit on Tuesday, citing a $1.6 billion pretax charge tied to a classified Aeronautics program and international helicopter contracts. The defense giant also slashed its full-year operating profit forecast by $1.5 billion, or 18%, to $6.65 billion, sending shares down more than 8%2. According…