UnitedHealth profit, forecast shine, shares leap | Reuters (Reuters) - UnitedHealth Group Inc's (UNH.N) quarterly profit crushed estimates, fueled by growth across its health plans and continued benefits from Americans' moderate use of healthcare services, and its shares soared as much as 10.5 percent to a three-year high. ... "It was a great quarter," Gleacher & Co analyst Joseph France said. "The question has been what is enrollment going to look like and what are medical costs going to look like. And I'd say this pretty much confirms, at this point at any rate, the best hopes that you could have had." Shares of rivals rose after the report, with WellPoint Inc (WLP.N) up 3.6 percent, Aetna (AET.N) rising 4.6 percent and Coventry Health Care (CVH.N) climbing 5.3 percent. The report was the first among large insurers under new spending rules, created by last year's healthcare overhaul law, and indicated that the companies could post strong results despite operating under the new regulations. The rules require insurers meet certain thresholds, known as medical loss ratios (MLRs), for spending on medical care as opposed to administration and profit. UnitedHealth said it had factored potential payments under the law into its quarterly results and forecast.