UPDATE 1-France's Viadeo buys Canada's Unyk social website

* Has more than 25 million users after deal

* Financial details of cash-and-shares deal disclosed

* Economic crisis has boosted social networking sites (Adds details, background, CEO quote)

By Tarmo Virki, European technology correspondent

HELSINKI, Oct 13 (Reuters) - French company Viadeo, which runs a social networking website aimed at professionals, has acquired Canadian peer Unyk, to become the second-largest professional social-networking company globally after LinkedIn.

Viadeo said on Tuesday it will have more than 25 million users after the deal, and its network was growing by more than 1 million users each month. LinkedIn has some 45 million members.

The economic crisis has sparked a spike in use of online social networks as people hedge against losing work and laid-off employees seek jobs.

"The global economic crisis has had an impact on all our members, and over the past 12 months we've seen not just an increase in the numbers joining Viadeo, but our members are engaging with each other online more than ever before," Chief Executive Dan Serfaty told Reuters.

Viadeo -- which did not disclose financial details -- said the cash-and-shares deal included 16 million users, a smart address book feature and contact synchronization technology.

"This acquisition is highly complementary and more than doubles our subscriber base," Serfaty said.

"We have significantly strengthened our market position and offering, particularly throughout Mexico, Brazil and India," he said, adding the company now has 4 million users in North America.

Viadeo entered the Chinese market through acquisition of local company Tianji in December 2006, and it acquired India's top professional networking site ApnaCircle.com earlier this year.

Viadeo said it was currently profitable and expected the deal to boost profits in the first year.

Founders and management own one-third of Viadeo, with the rest being held by AGF Private Equity, Ventech, CREADEV and others.

Quebec-based Unyk started in 2005 by its current chief executive and main shareholder Sebastien Brault. (Reporting by Tarmo Virki; Editing by Dan Lalor and Maureen Bavdek)