Officials at LinkedIn said the online business network’s corporate solutions group will soon offer four additional recruiting-related upgrades for business customers, starting with customizable company information pages that corporate customers can configure to match a job opening to the profile of the LinkedIn member reading the material.

The privately held, Mountain View, California-based company will also offer an improved e-mail marketing campaign tool that lets corporate customers tap into LinkedIn’s existing InMail network to broadcast job openings or other messages to its 33 million members. Rounding out the new features are an expanded banner advertising program and a flat-fee annual subscription for job board postings.

The additions come almost a year after LinkedIn introduced Recruiter, a software-as-a-service applicant tracking-style tool with search, collaboration and tracking features. The pay-per-seat service allows recruiters to do such things as send messages to LinkedIn members, store information on prospective candidates in electronic files, share data with co-workers and create job-offer templates.

At least one recruiter familiar with the new services worried that they could potentially backfire and turn off LinkedIn’s members by making the service seem too commercial. But company officials maintain they’re being sensitive to those concerns.

“Anything we do to make money must be beneficial to the free-network membership,” said Mike Gamson, head of LinkedIn’s corporate solutions group. “The talent management platform, it’s another reason to be on the service, because someone’s more likely to find their dream job here.”

LinkedIn has recently been adding a million new members every two weeks, and officials say more than 829,000 HR professionals and 521,000 corporate recruiters now use the network. But LinkedIn remains only a fifth the size of Facebook, which recently topped 150 million users.

When it comes to recruiting and social networks, however, size isn’t everything, said William Uranga, talent acquisition director at digital video recording service TiVo, a LinkedIn corporate customer.

Since Uranga started using Recruiter, LinkedIn has grown to account for about 10 percent of his yearly hires. When it comes to recruiting, Facebook doesn’t compare, Uranga said. LinkedIn is all business, and Facebook isn’t, he noted.

“If Facebook were to wake up, maybe they could build it, but they haven’t,” Uranga said.

Ultimately, it could be job boards such as Monster, CareerBuilder and Yahoo HotJobs that are the big losers if LinkedIn’s expanded recruiting tools catch on, said Jim Durbin, a recruiter-turned-social media consultant who blogs at Social Media Headhunter.

“People who are on it trust companies that are on it more than a job posting on a job board,” Durbin said. “Boards are filled with fake jobs and fake recruiters. Top candidates don’t want to hang out there anymore. On LinkedIn, you cut down that signal-to-noise ratio.”