Danske is under investigation in several countries, including the United States, over some 200 billion euros ($241 billion) of suspicious transactions that passed through the bank's tiny Estonian branch between 2007 and 2015.

Late last year, the bank completed a year-long internal investigation into its non-resident portfolio in the now shuttered Estonia branch and handed it over to authorities.

But the lender said on Wednesday it could be required to "undertake further internal investigation in 2021".

"That definitely disappoints me," Jyske Bank analyst Anders Haulund Vollesen told Reuters.

"I had hoped that we would see a clarification on this, and this prolongs the overhang in the stock for a while yet, so that's a shame," Vollesen said.

Danske reported first-quarter profit above expectations on higher fee and trading income, but kept its full-year forecast.

"Raising the guidance seems totally obvious, I had kind of hoped they would start out with a slightly bigger bang," Vollesen said, who said the results were good despite lagging net interest income.

Danske shares were down 0.65% at 0706 GMT.

"We saw a positive income development across our business and our cost measures continue to have an effect," newly appointed Chief Executive Carsten Egeriis said.

Egeriis took the helm earlier in April after former CEO Chris Vogelzang, who was hired to clean up the bank following the Estonia case, quit after being named a suspect in an investigation into alleged money-laundering at his former bank ABN Amro.

"We are making progress with the execution of our 2023 ambitions as planned," Egeriis said, referring to the bank's strategy of cutting costs, increasing profitability and becoming more efficient.

Operating expenses fell 2% in the quarter to 6.3 billion Danish crowns ($1.02 billion), while net profit came in at 3.1 billion crowns, above an average of 2.67 billion forecast by analysts in a Refinitiv poll.

($1 = 6.1573 Danish crowns)

($1 = 0.8291 euros)

(Reporting by Nikolaj Skydsgaard. Editing by Carmel Crimmins and Mark Potter)

By Nikolaj Skydsgaard