The move comes amid a wider rethink in the aerospace industry on whether the powerful but delicate backup energy systems are technically "mature," they said.

An Airbus spokesman said the company would study and evaluate the outcome of the ongoing US battery investigation. "Let's not get ahead of ourselves," he said.

Airbus said last week it had a plan B and time to respond to any rule changes.

France's Saft, which makes both the new and old generation of batteries for Airbus, did not immediately respond to requests for comment.