Olympus Corp's losses on securities investments mounted to more than 100 billion yen ($1.3 billion) at one point, the Nikkei business daily said on Wednesday, citing sources close to the matter.

Olympus, engulfed by a scandal that has brought the 92-year-old company to its knees, admitted the previous day to using M&A transactions to conceal past losses.

But Olympus President Shuichi Takayama declined to comment at a Tuesday news conference regarding who had initiated the concealment schemes, how the losses had occurred, or the amounts involved before an external panel completes an investigation into the deals.

Shares in Olympus were untraded amid a glut of sell orders early on Wednesday. The previous day, Olympus slid by its daily limit, dropping 29 percent to end at a 16-year low of 734 yen.

The camera and endoscope maker has lost almost three quarters of its market value since its British former CEO, Michael Woodford, went public with his suspicions about the transactions after he was dismissed last month.

Olympus declined to comment on the Nikkei report on Wednesday.

(Reporting by Isabel Reynolds and Nathan Layne; Editing by Edwina Gibbs and Edmund Klamann)