Boeing has informed its customers that the delivery of its sophisticated Dreamlier jets could be delayed, reinforcing concerns on the impact of the safety investigations.

The company did not suggest any dates for the deliveries to resume, but according to a Wall Street Journal report that cited an unnamed individual, airline companies may have to wait more than three months to receive their orders.

"We have informed our customers expecting 787 deliveries in the near term that those aircraft either have been or are at risk of being delayed," Boeing spokesman Marc Birtel said.

"We are staying in close communication with our customers as we work towards an approved means of compliance with the FAA Airworthiness Directive and develop a plan for resumption of 787 deliveries".

Dreamliner jets across the globe were grounded in January, after some battery-related issues resulted emergency landing of a 787 aircraft in Japan and fire in another one in Boston. The issues had prompted US and Japanese regulators to launch an enquiry into the matter and Boeing to suspend its deliveries to customers.

According to multiple media sources, Thomson Airways, a subsidiary of Britain's TUI Travel has said that the delivery of its first 787 scheduled for this month has been extended without a final date. Norwegian Air Shuttle said Boeing indicated that its order could be delayed due to an investigation by US regulators. Both the firms are reported to be considering contingency plans.

The delay is expected to be a major financial concern for Boeing, which normally receives payment once the aircraft is delivered. Despite the halt in deliveries, the company continues to manufacture five 787s a month, holding them at its facility in Everett.

The issue could also add to the US economic concerns as Boeing is the country's largest exporter and a delay in its products could hurt the total shipments. The firm delivered 23 Dreamliner jets from October to December 2012, according to the Wall Street Journal. At an estimated sales price of around $115m after discounts, Dreamliner's overseas sales could have been around $2.1bn in the final quarter, accounting for about 0.5 percent of total US goods shipments in the period.