Giken Sakata (S) said it had been told by substantial shareholder, Miyoshi Precision, that it had sold its entire stake of 69.9 million Giken shares.
The sale, transacted today, was approved by Miyoshi's shareholders at a meeting on March 7.
The disclosure was in response to a Singapore Exchange query over Giken's recent share price gyration.
"Miyoshi will be submitting the relevant information to the company within the next 24 hours. We will then make the necessary announcement via SGXnet," said Giken.
"We also understand that Miyoshi will also be making an announcement on the share sale within the next 24 hours."
Giken ended 41.5 per cent higher at 9.2 cents on turnover of 71.4 million shares.
Miyoshi shares were unchanged at 5.2 cents, with only 150 lots changing hands.