There were no signs so far that the diplomatic crisis would impact the deal, which was struck last month, the senior manager, who is close to the German firm's owners, said.

A coalition of Arab states led by Saudi Arabia and the United Arab Emirates allege Qatar funds terrorism and is aligning itself with Iran. They have blockaded its borders to cut off food imports and banks have been advised not to do business with Qatari institutions.

Qatar holds 14 percent and Saudi Arabia 10 percent of the merged company and both are represented on the supervisory board of what is now the world's fifth biggest container shipping line.

The next steps in the merger involve the inclusion of UASC's transport volumes on Hapag-Lloyd's IT platform and the establishment of new headquarters for the Middle East region as well as staff relocations.

Hapag-Lloyd's owners are Chile's CSAV (>> Compania Sud Americana de Vapores SA), the city of Hamburg, investor Klaus-Michael Kuehne and tourism group TUI , along with some minority investors.

"We are confident that we will be able to ensure complete integration by fourth quarter 2017," Hapag-Lloyd said in a letter to shareholders seen by Reuters, which maps out a timeline up to October.

Shipping giant Maersk Line, part of A.P. Moller-Maersk (>> AP Moller-Maersk), said Friday it will begin container shipments to Qatar from Oman, avoiding trade restrictions imposed on the Gulf state by Arab countries.

(Reporting by Jan Schwartz; Writing by Vera Eckert; Editing by Harro ten Wolde and Alexander Smith)