The number of well-paying job openings in Minnesota rose dramatically in 2012, driven by rising demand for high-skill workers like software developers, mechanical engineers, nurses and actuaries.

Nearly one in five job vacancies in the state offers a median wage of $25 per hour or more, and the total available jobs paying that much rose 64 percent in 2012, according to figures released Thursday by the Minnesota Department of Employment and Economic Development.

"There definitely seems to be an uptick in hiring in some of these higher-skill and higher-wage occupations," said Oriane Casale, a labor market economist for the state.

Computer-related skills, especially coding and Web development, are at a premium. The number of vacancies for software application developers nearly doubled in 2012 to 666 openings. At the same time, the median wage offer rose more than $4 an hour, to $33.59 an hour, which comes out to just under $70,000 per year.

Companies are becoming more desperate to keep highly skilled workers, and they're getting into bidding wars with each other, said Jim Kwapick, a senior vice president for Robert Half International, a professional services staffing firm.

"In the professional disciplines, we're seeing increasingly more counteroffers," Kwapick said. "With the dearth of some of these high-skilled candidates, it's pushed up the effort to retain them, and sometimes that's manifested in dollars."

Marketing managers, operations managers, financial managers, IT and network administrators, and even chief executives are all in higher demand than they were a year ago.

Overall, the number of job vacancies in Minnesota rose 18 percent compared with a year earlier. The Department of Employment and Economic Development said employers reported 58,860 job vacancies in the fourth quarter of 2012, compared with 49,890 openings during the same period in 2011. There were 2.6 unemployed people for each vacancy, compared with 3.2 unemployed people per vacancy a year earlier.

Yet the labor market continues to grow fastest at the high and low ends of the income spectrum.

"It is truly a tale of two labor markets," Kwapick said.

For instance, the number of openings for food preparation and serving related jobs rose 47 percent in 2012, ending the year with 6,494 vacancies. But median wages for those openings fell — from $7.90 per hour to $7.58 per hour.

More than 30 percent of all vacancies in Minnesota offer $10 an hour or less, and some 39 percent of all available jobs are part-time.

"Low income workers are often patching together part-time jobs," said Carrie Scheffler, director of the Employment Action Center, which helps laid-off workers, youth, veterans and immigrants find jobs. "Many times retail positions, or fast-food restaurants, it's not enough to meet their needs."

The state's analysis found that 34,400 of job openings, or 58.4 percent of the total, are in the seven-county Twin Cities metropolitan area, while 24,460 were in outstate Minnesota. In the Twin Cities, there were 2.4 unemployed people per vacancy, down from 2.9 a year ago. Outstate Minnesota had 3.0 unemployed people per vacancy, down from 3.7 a year ago.

Health care providers had the most job openings, about a fifth of the state's total. Retail accounted for 14 percent; accommodation and food services, 11.5 percent; manufacturing, 9.2 percent; and finance and insurance, 7.6 percent.

The most job vacancies were reported by firms with between 10 and 249 employees, which accounted for 62.1 percent of the openings. Large firms accounted for 23.6 percent of the openings, while small firms with fewer than 10 employees had 14.2 percent of the openings.

The state conducts its job vacancy survey twice a year. The latest study surveyed 10,300 employers.