Helsinki District Court on Friday acquitted 10 defendants in a criminal case against Nokian Tyres' CEO and other members of management who were suspected of not appropriately disclosing information to the stock market.
The charges included aggravated misconduct and insider trading offences.
The case was related to a scandal in 2016, when it was revealed that tyre review tests on the firm's products had been manipulated to ensure high ratings.
Ari Lehtoranta, who was the company's CEO in 2015-2016, as well as board members, faced criminal charges for not disclosing the test manipulation before it came out in the press. Lehtoranta is no longer at Nokian Tyres.
News of the tyre test manipulation scandal first came to light after business publication Kauppalehti issued a report on the topic in early 2016.
The prosecutor said that the company's leadership should have disclosed information about the test manipulation immediately, as it would have affected the value of the firm's stock shares.
Four members of the company's management team were accused of selling off their shares in the company in the autumn of 2015 while being aware of the test manipulation practices.
In its decision on Friday, the district court said it had not been proven that the firm manipulated the test results nor that management members did not disclose such information before Kauppalehti published its story on the matter.
Further, the court said it did not find any indication of fraud between Nokian Tyres and the company that carried out the tests.
In a stock exchange release issued on Friday, Nokian Tyres said it would not comment about the topic.