A2 Milk's share price fell sharply after it said the US Food and Drug Administration had deferred the company's request to send infant formula to the United States to help alleviate the product shortage there.
In a statement to the NZX, a2 Milk said it received notification from the FDA deferring further consideration of the request for enforcement discretion to import infant milk formula products.
"The company has also subsequently been advised by the International Dairy Foods Association that equivalent letters have been sent to all pending enforcement discretion applicants, indicating that the FDA is deferring any further review at this time of all pending applications," a2 Milk said.
By late morning Milk's shares were down 58c or 10.3 per cent at $5.05.
The stock has been climbing sharply over the last month on the back of expectations that it would gain FDA approval, along similar lines to the approval given to its Australian competitor, ASX-listed Bubs.