Janel Landon, who runs a small PR consultancy in Chicago, has long been aware of the potential of online networks: Now in her mid-50s and facing a global recession, she's decided to sign up.

"Given the state of the economy, I recently decided to jump on board," said Ms Landon. "Professional networking is a 'must do' during unstable economic times."

The economic crisis slamming firms across the globe has sparked a spike in usage of professional networks - Xing and LinkedIn are key sites - as people hedge against losing work and laid-off employees seek jobs.

US unemployment hit a new 14-year high last month and according to online job advertising firm Monster, recruitment activity on the web plunged to its lowest level in nearly three years. Jobless rates are also rising in Europe.

Traffic on the world's top professional web networks has surged since the financial crisis started to make headlines, with top player, privately held LinkedIn, notching 25 per cent more registrations in September than forecast.

"Nobody has ever seen anything like this before," said Kevin Eyres, head of LinkedIn's operations in Europe. "Now we are growing by almost one new user each second."

Membership on LinkedIn has jumped to more than 31 million from 18 million at the start of the year, growing fastest in the financial services, media, education and technology fields, Mr Eyres said. The firm has not disclosed any financial details.

"Given that a lot of professionals are currently losing or are worried about losing their job, it makes sense that career-focused social networks such as LinkedIn should see a boost in traffic," said Martin Olausson, director of the digital media strategies unit at research firm Strategy Analytics.

He estimated the size of the online professional social networking market at about €131 million this year.

Professional sites seek to distance themselves from social networks such as Facebook with their more sober approach, and by giving members more control over their profiles.

Richard Evans, director at UK-based Sheridan Evans Executive Search, said he has seen a rising number of requests to connect on professional Web networks: These are increasingly about the need for a job.

Sheridan Evans uses both LinkedIn and Xing, but also Paris-headquartered Viadeo and the largest address-book site Plaxo, to identify potential candidates. It has directed many people to their new jobs using such networks, Ms Evans said.

"The recruitment industry in general is being hit hard. In financial services it's clearly very bad. In construction it's bad. In retail it's getting bad," said Ms Evans, adding a shortage of senior management was supporting the headhunting business.

Already an estimated 150,000 jobs have been lost globally in the financial sector alone, with more widely expected to go in investment banking and trading.

Arun Patre, a 25-year-old analyst at a financial consultancy in India, said he has been looking for jobs on LinkedIn: "The economic situation has prompted me to widen my network as you would never know where things might turn lucrative."

Sign up to our free newsletters

Get the best updates straight to your inbox:
Please select at least one mailing list.

You can unsubscribe at any time by clicking the link in the footer of our emails. We use Mailchimp as our marketing platform. By subscribing, you acknowledge that your information will be transferred to Mailchimp for processing.