NEW YORK (AP)--Wanted: Truck drivers, plumbers, nurses, cashiers and the businesses that hire them.

After years of pitching themselves primarily to resume-toting professionals and their prospective employers, the big Internet job sites are trying to muscle into the recruitment market for blue-collar and service workers.

Monster.com will use an ad during this Sunday's Super Bowl to tout changes in its listings and application process geared to workers paid by the hour. The new campaign follows the December launch by CareerBuilder.com of its own online recruitment tool for so-called "skilled and hourly" workers.

HotJobs.com, owned by Yahoo!, says it also is working to broaden its efforts in the hourly market.

The new focus comes as the online job boards struggle to generate business in an economy notable for its lack of new jobs.

"Last quarter, Monster's revenue was down almost 30%, year over year," said Matthew Litfin, an analyst with William Blair & Co. "Who can blame a company for trying to stem a decline of that magnitude?"

Monster and its rivals say they're wooing hourly workers out of logic, not desperation. Workers paid by the hour are 60% of the nation's labor force, and more of them are frequenting the Internet.

"It's the size and the revenue potential of the market, regardless of how the economy is doing, that's drawing people there," said Matt Ferguson, CareerBuilder's chief operating officer.

The hourly market "represents a huge potential target," said Peter Weddle, author of Weddle's Guide to Employment Web Sites. "Rather than a sign of weakness on the part of the job boards, I think it is a sign of maturation. ... They're trying to be more comprehensive."

To reach those workers, Monster, as well as HotJobs, are again using commercials during the Super Bowl, making them among the few surviving dot-com businesses still willing to spend heavily on advertising.

For the Web sites, the hourly job market--which they define broadly to cover everyone from construction workers to nurses--is largely fresh territory since most of those jobs are filled through newspaper classified ads or staffing agencies.

The first Internet job boards to venture in were specialty sites like constructionjobs.com, and employmentguide.com, affiliated with a chain of free ad circulars focused on the hourly market.

Monster edged into the market early last year, when it started a test site in the Cincinnati area. It was matched by The Cincinnati Enquirer newspaper, owned by Gannett Co., which started its own online hourly recruitment board. That site helped shape the expansion of CareerBuilder, owned jointly by the Gannett, Knight-Ridder and Tribune Co. newspaper chains.

Monster and CareerBuilder say there are important differences between the way hourly and salaried workers look for jobs.

Most hourly workers pursue jobs by filling out applications rather than creating and sending out resumes. So both sites allow job seekers to file an application that can be viewed by employers.

CareerBuilder, for example, lets an hourly job seeker create up to five "profiles," specifying their work preferences, experience and education. The information in the profile goes into a database for viewing by employers, and allows workers to see openings that match their skills.

The job boards acknowledge that some hourly workers don't have computer access, so they have set up phone-based services to accept applications. Monster also has bilingual call center operators who can help job applicants through the process.