As a result, Norwegian Air Shuttle said it will lease other aircraft to replace the 787 if they are not delivered in time to launch its long-haul service.
Boeing warned the Nordic carrier deliveries were uncertain because of the investigation by the US National Transportation Safety Board (NTSB).
"The extent of a possible delay and whether such delay will affect later deliveries is presently not known," Norwegian Air said in a statement on Friday morning.
"Norwegian is taking precautionary steps by planning for substitute aircraft capacity."
Sky News has confirmed that Virgin Atlantic has not received any correspondence from Boeing of a possible delay, and it still expects to take delivery of 16 787s from summer 2014.
The news comes just hours after US aviation officials cleared Boeing to begin restricted test flights of the grounded model to examine the batteries.
The decision late on Thursday followed an earlier one-off flight to move a 787 from Texas to Washington state, where Boeing is based.
Norwegian Air Shuttle added: "In the event that the 787 is not operational in time for Norwegian's services to New York and Bangkok replacement long-haul aircraft will be leased to ensure flights are operated as scheduled."
The carrier was scheduled to receive the first of eight Dreamliners in April and the firm has already sold hugely discounted tickets for its first overseas flights as it aims to take on traditional legacy carriers.
Authorities grounded the Dreamliner worldwide on January 16, after a series of battery incidents, including a fire on board a parked Japan Airlines (JAL) 787 in Boston and an in-flight problem on another plane in Japan.
Officials in Japan are also investigating the aircraft after a rash of incidents aboard Dreamliners operated by All Nippon Air (ANA) and JAL.
The two Japanese airlines operate nearly half of the 50 Dreamliners in service, with ANA owning the most with 17, some 7% of its fleet.
Around a third of components on the composite-construction model were made in the Asian country, including the lithium-ion batteries that have become a central concern.
ANA said last week that it lost around $15m (£9.5m) in revenue as a result of the Dreamliner grounding, while JAL said it was expecting $7.6m (£4.82m) to be shaved from its operating profit in the year to March 31.
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