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

Companies and governments in December posted 3.38 million jobs - near the three-year high reached in September - the Labor Department said Tuesday. Some 3.12 million jobs were advertised during the previous month. Job openings in the private sector reached the highest point in almost 3 1/2 half years.

Still, overall hiring slipped, and the number of people who quit their jobs also declined. That suggests that 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 that 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 13.1 million people were still 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 usual ratio is about 2-to-1.

Employers generally take one to three months to fill job openings. December's big jump in postings is likely one reason that January's jobs report was healthy. But it also suggests that job growth may continue in the coming months.

Job openings have rebounded since the recession ended in June 2009, rising 39 percent since then. But they are still far below the pre-recession levels of roughly 4.5 million.

And hiring hasn't kept up with job openings: It has risen only 11 percent since June 2009.

The slow recovery in hiring may be one reason the job market still seems sluggish to many people, particularly those out of work, even as the unemployment rate has fallen for five months straight.

Any net job gains are still, of course, a good sign. They mean payrolls are growing, and consumer spending can grow. So can the economy.

But the low turnover helps explain why the job market may not feel much better to many people - especially those without jobs.