About 170 people have been made redundant after Thomson Local, which produces business directories, went into administration.
Staff were summoned to the firm's headquarters in Farnborough, Hampshire, where they were told the news.
Database specialists Corporate Media Partners has since bought out the firm saving about 340 jobs.
All products and services purchased from Thomson Local will continue, a message on its website said.
As part of the deal, the firm's printed directories and digital products will remain.
According to its website, Thomson Local has been operating for more than 25 years with 174 editions of its directory delivered to more than 22 million homes each year.
It has 10 regional sales offices throughout the UK but details of where the job losses will be felt have not been revealed.
Thomson Directories was the UK subsidiary of the cash-strapped Italian yellow pages company Seat Pagine Gialle.