WASHINGTON (MarketWatch) - The U.S. economy gained 243,000 jobs in January and the unemployment rate slipped to 8.3%, the Labor Department said Friday. Economists surveyed by MarketWatch had forecast the U.S. would add 121,000 jobs last month, with a jobless rate of 8.5%. The private sector boosted payrolls by 257,000, led by large increases in manufacturing, professional services, leisure and hospitality and health care. Average hourly earnings rose 0.2% to $23.29 and hours worked were unchanged at 34.5. Job gains for December and November were revised up by a combined 60,000. The U.S. created 1.82 million jobs in 2011, based on newly revised tax and other data, compared to an originally reported increase of 1.64 million.