UPDATE 1-Malaysian bank CIMB says chairman Nazir Razak to step down by year end

end@ (Adds comment from chairman, background)

KUALA LUMPUR, Sept 24 (Reuters) - CIMB Group Holdings Bhd , Malaysia's second biggest bank, said on Monday its chairman Nazir Razak has decided to step down by the end of the year after 29 years at the bank.

Nazir, the brother of former Malaysian Prime Minister Najib Razak, has been CIMB's chairman since 2014, before which he was the chief executive for 15 years.

Under his leadership, CIMB grew through rapid acquisition from a boutique firm to a regional bank with a strong presence in Southeast Asia. Nazir remained a key figure in the bank when he took over as chairman even though he had stepped away from day to day duties.

"It was always going to be hard to find the perfect moment for me to leave CIMB not too soon, not too late but always with the firm's best interest in mind," Nazir, 52, said in a statement.

Nazir said he had decided to leave on completion of the bank's four-year recalibration plan, launched in 2014. His term was set to end in August 2019.

CIMB said the board would decide on the next chairman and the exact date of handover in due course.

Nazir's move to step down comes amid a management shake-up at Malaysian companies following an unexpected loss by Najib in the general election to Mahathir Mohamad in May.

Officials seen as close to the previous administration have been purged in recent months.

The central bank, sovereign wealth fund Khazanah Nasional - CIMB's biggest shareholder - and the country's largest fund management firm Permodalan Nasional Bhd have all seen management changes since May.

In 2015, Nazir went on a leave of absence after the Wall Street Journal reported that he received around $7 million from his brother Najib before the 2013 general elections and disbursed the funds to other politicians.

An independent review into money transfer concluded that Nazir "did not misuse his position" and there was no inappropriate use of the bank's resources, following which Nazir resumed his duties as chairman.

Najib is facing several charges of money laundering, abuse of power and criminal breach of trust as part of Malaysia's investigation into state fund 1MDB. He has pleaded not guilty to all the charges and has consistently denied wrongdoing. (Reporting by A. Ananthalakshmi Editing by Mark Potter/Keith Weir)