An Omani state-owned fund has told TUI AG in writing that it wants to buy a stake in Hapag-Lloyd from the German tourism group, a person familiar with the matter said.

There is no binding agreement yet, though, the person said, and China's HNA Group is also still in the running to buy a stake in the world's fifth-largest container shipping group, the person told Reuters.

German tourism group TUI AG aims to exit its investment in Hapag-Lloyd but has said it would take its time to decide whether to sell or float its 38.4 percent stake in Hapag-Lloyd.

Reports surfaced in April that TUI was in talks with China's HNA Group, parent of Hainan Airlines , and Oman.

German daily newspaper Financial Times Deutschland earlier reported that HNA would want a majority stake in Hapag-Lloyd, which TUI cannot offer.

TUI and Hapag-Lloyd declined to comment. HNA Group was not immediately available to comment.

Sources have told Reuters that bids for the stake are due by the end of July.

"But that is not set in stone," the person familiar with the negotiations said on Thursday.

The shares of Hapag-Lloyd that TUI does not own are held by Albert Ballin, a group of Hamburg-based investors led by Klaus-Michael Kuehne, the majority owner of Swiss logistics group Kuehne & Nagel . (Reuters)