Export New Zealand executive director Catherine Beard said exporters most at risk were those with perishable goods, such as seafood and flowers, or high-value, high-tech, time-sensitive equipment.
However, she said it was too early to put a cost on the loss of flights into Europe for business, though some of those affected were already seeking customers closer to home.
"Some exporters are currently being told of delays of two to three weeks, while those with weekly shipments into UK supermarkets have had those consignments halted.
"There's also a seafood trade show in Brussels in 10 days' time that neither product nor people will be able to attend.
On the positive side, the majority of New Zealand export volume - such as chilled and frozen meat, dairy and kiwifruit - goes via ship, and airfreight to the Asia Pacific rim and is flowing well."
Flight disruptions in Europe are starting to interfere with the export of some Dunedin products, including fish and high-end electrical goods, and city tourism could also be affected.
Otago Chamber of Commerce chief executive John Christie said some tourism operators had had bookings cancelled.
Any loss of inbound tourism during the shoulder season could have unwelcome effects.
The effect on Otago largely depended on how long the flight disruptions lasted, he said.
Southern Clams administration manager Bruce Inglis, of Dunedin, said a scheduled air shipment to London supermarkets last Friday was postponed, with the shellfish deliberately left unharvested.
The delay would have "pretty minimal" effect on the firm, but continuing flight disruptions were likely to interfere with the company's planned presence at the seafood show in Brussels.
Perreaux Industries, a Dunedin manufacturer of state-of-the-art amplifiers and electrical equipment, was asked by its French agent to supply products for an audio trade show being held in France on April 28.
However, managing director Martin van Rooyen said it would be difficult to get the equipment there on time.
Up to 10 tonnes of export-quality New Zealand lamb is stranded in transit at airports across the world, and South Island farmers' co-operative Alliance Group has stopped production of its lamb bound for Europe by air-freight.
Marketing manager Terry O'Connell said lamb shipments had been caught in Singapore, Los Angeles and Christchurch, and the company would try to sell the product where it was, or return it to New Zealand.
But New Zealand King Salmon Company in Nelson has reported a boost as it fills orders which European companies have not been able to send.
Sales and marketing general manager Don Everitt said his company's exports might increase as much as 50% in volume in the next few weeks.
And Eastern and Global Flower Exporters managing director Greg Keymer told Radio New Zealand his business had enjoyed a similar windfall.
"In the last 24 hours we've had a flurry of activity from the east coast of North America in particular looking for New Zealand orchids because they simply can't get any from Holland," he said.
Insurance Council chief executive Chris Ryan expected an influx of claims from businesses.
"The insurance companies are not only covering travellers, but also the cargo that's being transported both in and out of the country on these planes."
