The number of available jobs in the United States jumped in December to near a three-year high, supporting other data that show a brighter outlook for hiring.

Companies and governments posted 3.38 million jobs in December, the Labor Department said Tuesday. That's up from the 3.12 million advertised in the previous month and nearly matches the three-year high reached in September.

Job openings in the private sector reached the highest point in almost 3 1/2 years.

Still, overall hiring slipped, and the number of people who quit their jobs also declined. That suggests the job market still isn't as dynamic as it was before the recession. Manufacturers, retailers and professional and business services all posted gains. Professional and business services include temporary jobs. But they also include high-paying positions, such as architects, engineers and accountants.

The report on job openings follows Friday's optimistic employment figures. Those showed employers added 243,000 net jobs in January, and the unemployment rate fell to 8.3 percent.

December was also a big month for hiring, but there were still 13.1 million people unemployed that month. That means an average of 3.9 people competed for each open job in December, the first time in four years that ratio was below 4-to-1. In a healthy job market, the ratio is usually around 2-to-1.

It generally takes up to three months for employers to fill openings. December's jump in postings is probably one reason January's jobs report was healthy.