Boeing Co. had to postpone this week\'s inaugural delivery of the 747-8 freighter, a jet already two years behind schedule, after its initial customer refused to accept the first two planes.Boeing had to cancel three days\' ceremonies on Saturday because of \"unresolved issues\" with Cargolux Airlines International, said spokesman Jim Proulx. The carrier was scheduled to fly its first load of freight on the new plane out of Seattle on September 19 and take delivery of a second jet two days later.Proulx declined to comment on the reason for the dispute, and Cargolux would only say that there had been \"contractual issues\" that compelled its board, which met on Saturday, to reject the planes. The clash mars the arrival of the newest and biggest version of the jumbo jet that, with its iconic hump, has been Boeing\'s marquis model since its inception in the 1960s. It also comes after numerous struggles at the company, including a three-year setback to its 787 Dreamliner, inroads into its customer base by Airbus and a shift in its new-jet strategy. \"It\'s horrendous,\" Ken Herbert, an analyst with Wedbush Securities in San Francisco, said in an interview. \"Just when you finally thought they were going to turn the corner, this happens.\"The 747-8 freighter won certification last month from the US Federal Aviation Administration to enter commercial service, capping a two-year, $2.04 billion (Dh7.48 billion) delay for Boeing\'s biggest plane ever. Luxembourg-based Cargolux was to be the first to receive the jumbo jets, which feature new engines and a stretched upper deck and wings. \"We continue to work with Cargolux and look forward to delivering its airplanes,\" Boeing\'s Proulx said on Saturday from Everett, Washington, where the jets are built. Financing, secured through JPMorgan, has been put on hold, Cargolux, Europe\'s largest freight-only carrier, said yesterday.\"In the event that the issues cannot be resolved in a timely manner, Cargolux will source alternative capacity to fully meet customer demand and expectations ahead of the traditional high season,\" the company said in a statement. Qatar Airways Ltd. took a 35 per cent stake in Cargolux in June and said it planned to start converting 20 Airbus A330 jetliners into freighters next year to accelerate its expansion into logistics.Trials continue on Boeing\'s 747-8 Intercontinental passenger model as crews test different systems than on the freighter, including climate control and airflow balancing.