Guardian News & Media is on the lookout for a buyer for ContentNext Media, which publishes news website paidContent.

The publisher, which bought the company three years ago, said it is seeking a buyer so it can focus on building the Guardian’s US readership.

ContentNext Media, which also publishes site including paidContent:UK and mocoNews, is valued at around $20m (£13m), according to some estimates. Its fourth site, contentSutra, is dedicated to the Indian market but doesn’t have its own staff.