UnitedHealth ( UNH) posted a 47% fourth-quarter revenue jump and said its operating margin for the quarter rose to 11%.The Minnetonka, Minn., health insurer declined to offer per-share earnings data, saying it is working on completing restatements of past financials tied to the company's previous omissions in reporting stock-based compensation expense. But the company said it made $1.2 billion with 1.4 billion shares outstanding -- putting its earnings per share at 86 cents on a back-of-the-envelope basis, a penny better than the Wall Street consensus estimate. Revenue rose to $18.1 billion, against the $18.2 billion Thomson Financial target. UnitedHealth said that latest-quarter results include a total of approximately $50 million in cash and noncash expenses related to stock option matters, including a $13 million charge related to historical stock options under FAS 123R. The fourth-quarter consolidated medical care ratio of 79.9 percent, which includes all risk-based businesses and products, declined 120 basis points on a sequential quarter basis, driven by the seasonally strong performance of Medicare Part D.