Lion Nathan has told officials at the Australian Securities Exchange that it has no concrete explanation for a suddent drop in the brewer's share price.

The stock exchange authority wrote to Lion Nathan yesterday (16 December) to ask the firm whether there was any unanounced information that could have sparked the fall.

It said shares rose to a high of A$8.90 (US$6.2) on 11 December and then dropped to a low of $7.62 at the time of writing.

Lion Nathan said today that it was in compliance with disclosure rules. It added: "The company is not aware of anything that may have caused the price change of its securities, however, one possible explanation is that the secturities went ex-dividend on 15 December."

The group's shares closed at $7.70 on the Australian exchange today.

Lion Nathan, which is owned by Japan's Kirin Holdings, recently made an $8bn takeover bid for Coca-Cola Amatil, but the move has been rejected.