HNA Group, the parent of China's fourth-largest airline Hainan Airlines Co Ltd, has joined the fray in bidding for Hochtief AG's airports business.

HNA's airport unit was among those shortlisted to move to the second round of bidding for Hochtief's airport assets, an HNA executive with knowledge of the deal told Reuters.

The executive did not disclose the value of the deal, but Adam Tan, an HNA executive director, put a price tag of more than 1 billion euros ($1.42 billion) on it, according to the Wall Street Journal.

Another source with knowledge of the deal said Hochtief could expect bids of up to 1.3 billion euros.

Hochtief confirmed it had received bids for the assets, which include its stakes in airports in Athens, Budapest, Dusseldorf, Hamburg, Sydney and Tirana.

"We are satisfied with the process and expect we can reach a deal this year," a Hochtief spokesman said.

The HNA executive did not name the other bidders, but sources told Reuters last month that Vinci SA -- the world's largest public works group -- and Frankfurt airport operator Fraport AG had made offers.

Fraport declined to comment.

A source close to the transaction said in July that London Gatwick owner Global Infrastructure Partners had teamed up with Allianz to make a bid, though the consortium is not seen among the front-runners.

Earlier in August, HNA joined up with Bravia Capital of Hong Kong to take over a shipping container leasing business, partly owned by General Electric Co . (Reuters)