Swedbank said in February it had reported its former chief executive, who was fired earlier that month, to authorities for suspected financial crimes.

"The assessment of the information in the investigation is that it does not provide sufficient evidence to show that a crime of insider trading has been committed," Economic Crime Authority spokeswoman Katinka Wall said.

"It has not been possible to show that the person in question has had insider information relating to the specific company in which there have been transactions of shares."

In an emailed statement Wolf said he had complied with all laws and rules.

"I am relieved that it is now proven that I am completely innocent of the charges brought against me," Wolf said.

Swedbank's finance chief and chairman have both left the bank since Wolf's departure.

Shareholders voted in April against discharging Wolf and the outgoing chairman from liability, keeping the door open to suing them for damages.

The Financial Supervisory Authority is conducting a separate investigation into how the bank handles conflicts of interest, an FSA spokeswoman said.

(Reporting by Stockholm Newsroom; editing by Niklas Pollard and Jason Neely)