China Eastern Airlines Corp Ltd and Air China Ltd have restarted doing business with online travel agency Qunar Cayman Islands Ltd after months of closure.

An informal alliance to boycott Qunar was formed at the start of the year, after China Southern Airlines Co Ltd announced in December it was shutting down its online links with Qunar because of many complaints it received from customers who bought tickets through the booking platform.

That move was followed several days later by another eight carriers, including Air China and China Eastern. They issued similar statements suspending their business with Qunar and advising passengers to buy tickets via their official website or authorized agents.