MOUNTAIN VIEW, Calif. >> LinkedIn is launching its site in simplified Chinese, the written characters used on the mainland, as it works to expand in the country with the world’s largest Internet population.

The professional networking service hopes to broaden its reach in the country with more than 140 million professionals, 4 million of whom use LinkedIn. Until now, the site in China was in English only.

LinkedIn Corp. acknowledges that expanding in China raises “difficult questions” because it will be required to censor content. It says it will be clear about how it conducts business in China and undertake “extensive measures” to protect members’ rights and data.

Two-thirds of LinkedIn’s 277 million users are outside of the U.S. Unlike Facebook, Twitter and other sites, LinkedIn has always been allowed to operate in China.