* Head of Danish banking unit Jesper Nielsen new interim CEO
* "Right decision" Danish pension fund says of change
* Danske's Aarup-Andersen seen as likely new CEO -reports (Adds quotes, details, general counsel exit)
By Teis Jensen
COPENHAGEN, Oct 1 (Reuters) - Danske Bank appointed an interim chief executive on Monday as it sought to reassure investors rattled by a $235 billion money laundering scandal and looking for a new leader.
Jesper Nielsen, the head of Danske Bank's domestic banking business, will take on the running of the bank while a replacement is found for Thomas Borgen, who resigned last month but was not originally going to leave with immediate effect.
"The bank cannot move on with rebuilding the trust in the bank before he (Borgen) is gone," said Jens Munch Holst, chief executive of MP Pension, which holds Danske Bank shares, said.
Borgen quit after an internal inquiry found that payments totalling 200 billion euros, many of which Danske Bank said were suspicious, had been moved through its Estonian branch between 2007 and 2015.
"I agree with the board that it is best for all parties that the chief executive is someone who can help follow decisions through to the end, and as I have resigned, that is not me," the 54-year-old said in a statement emailed to Reuters.
Borgen, who was in charge of Danske Bank's international operations, including Estonia, between 2009 and 2012 and became CEO in 2013, said last month that while he was cleared from a legal point of view, he held "ultimate responsibility".
Denmark's largest bank said Borgen has been relieved of his duties, while Nielsen will continue to work as Head of Banking DK and is not a candidate for the permanent CEO position.
"We are of the opinion that, with the situation the bank is in, it is best that the executive director is also part of the bank's future," chairman of the bank Ole Andersen said.
He added that finding a new CEO was progressing as planned, but a spokesman for the bank declined to estimate when a new CEO could be announced, or whether the appointment of an interim CEO meant that the board has widened the search for a new CEO.
British shareholder adviser Hermes EOS has urged the bank's board to explore suing senior executives over the money laundering scandal, the Financial Times reported on Monday.
Hermes EOS said it wanted the bank to emulate German engineering conglomerate Siemens, which sued several senior managers, including former chief executives and chairmen, over a large bribery scandal, the newspaper reported.
Hermes EOS did not respond to requests for comment.
Denmark's MP Pension said it will hold a meeting with Danske Bank this week and will ask "a series of critical questions to make sure the bank is doing what it can to clean up to ensure that a money laundering case will never happen again".
In another top level departure, Danske Bank said its chief legal adviser had also resigned.
"I have taken part in many of Danske Bank’s key cases in the past five years, and I feel it is time to move on in my career," Group General Counsel Flemming Pristed said.
"The recent Estonia case in particular has been very demanding, and it is a good time for me to stop now that a new CEO is to be appointed and the findings of the bank’s internal investigations into the matters at the Estonian branch have been announced," Pristed said in a statement.
Danske Bank has not named any potential permanent replacements for Borgen, but the head of its Wealth Management unit Jacob Aarup-Andersen has been named by some analysts and media including Danish online media Finans as a likely new CEO, although some say that at 40 he is too inexperienced.
Aarup-Andersen took up his role in April following a two-and-a-half year stint as Danske's CFO, and before that two years as CEO of its pension fund Danica.
After having obtained a master's degree in Economy at University of Copenhagen in 2002 Aarup-Andersen worked in London's financial district for amongst others Goldman Sachs for ten years before he returned to Denmark for a job as Chief Portfolio Manager at Danske's Capital unit in 2012.
Others mentioned by analysts and media outlets as possible candidates are the CEO of Danish mortgage lender Nykredit, Michael Rasmussen, the Head of European Fixed Income and Commodities at Morgan Stanley Jakob Horder, and Annika Falkengren who is the former CEO of Swedish bank SEB and a partner in Swiss bank Lombard Odier.
Morgan Stanley and Nykredit declined to comment, while Lombard Odier did not immediately respond. ($1 = 6.4278 Danish crowns) (Additional reporting by Emil Gjerding Nielson and Jacob Gronholt-Pedersen; editing by Jason Neely and Alexander Smith)