The number of available jobs in the United States rose in December to a near three-year high, the government said Tuesday. The Labor Department said companies and governments posted 3.38 million jobs in December, which is up from 3.12 million in the previous month and nearly matches the three-year high in September. Job openings in the private sector hit the highest point in about three and a half years. Manufacturers, retailers, and professional and business services all posted gains. The report supports other economic data that shows a better outlook for hiring. The unemployment report released Friday showed that employers added 243,000 jobs in January, and the unemployment rate fell to 8.3 percent. December may have been a big month for hiring, but 13.1 million people were still unemployed, meaning an average of 3.9 people competed for each open job that month. It was the first time in four years that the ratio was below 4 to 1. In a good job market, the ratio is usually around 2 to 1, economists say. It usually takes one to three months for employers to fill job openings, so December's dramatic jump was likely one reason January's job report was healthy. It also indicated that job growth could continue in the next few months. Job openings have risen 39 percent since the recession ended in June 2009, but they are still far below the level of 4.5 million before the recession.