UnitedHealth Group Inc., the No. 2 U.S. health insurer, said fourth-quarter profit rose 27% to $193 million, or 58 cents a share, beating forecasts of 55 cents, as it added customers and raised premiums more than medical costs increased. Revenue grew 9% to $5.43 billion. The Minnetonka, Minn.-based company increased premiums about 11% and still added more than a million customers, a 9% increase, in part because the company in 1999 dropped a requirement that customers call the insurer before seeking medical treatment. UnitedHealth also said it expects 2001 earnings of $2.48 to $2.52 a share, more than the average $2.45 estimate of analysts surveyed by First Call/Thomson Financial. Premiums will rise about 12% this year while benefit costs will rise about 11%, it said. With No. 1 insurer Aetna Inc. restructuring itself, investors are paying closer attention to UnitedHealth results as an indicator of how well the industry is keeping up with increases in the cost of medical care and prescription drugs. Shares of UnitedHealth rose $4.36, or 7.7%, to close at $61.10 on the NYSE.