NEW YORK — Nineteen companies caught writing fake reviews on websites such as Yelp, Google Local and CitySearch have been snared in a year-long sting operation by the New York Attorney General, and will pay $350,000 in penalties.

The Attorney General’s office set up a fake yogurt shop in Brooklyn, New York, and sought help from firms that specialize in boosting online search results to combat negative reviews.

Some search optimization companies offered to post fake reviews of the yogurt shop on sites such as Yelp.com, Google Local and IAC/Interactivecorp’s Citysearch.com, the Attorney General’s office said in a statement on Monday.  

The companies created online profiles and paid as little as $1 per review to freelance writers, some of whom were in the Philippines, Bangladesh and Eastern Europe, the Attorney General’s office said.

Yelp welcomed the crackdown, saying it was critical that the company protect the integrity of its content. It said it would continue to work with law enforcement agencies, as well as taking steps itself to combat fraud.