ALMATY, Jan 13 (Reuters) - Kazakhstan’s central bank fired the head of its investment management arm after he criticised the country’s authorities for drawing aggressively on the $64 billion state oil fund.

The National Investment Corporation (NIC) said in a statement on Wednesday the central bank, its sole shareholder, had dismissed NIC Chief Executive Berik Otemurat on Jan. 8

NIC did not say specifically why he was fired, but his dismissal came the same day interviews with him were published in the Wall Street Journal and the Financial Times. Otemurat could not immediately be reached for comment.

In both interviews, Otemurat urged the government and the central bank to invest the fund’s assets in riskier, higher-yielding assets. He also told the Wall Street Journal that the fund could be depleted in six or seven years.

According to central bank data, the fund’s assets peaked at $77.2 billion in August 2014 and have since dropped to $63.5 billion.

Otemurat also said in the Journal interview that the investment management firm created in 2012 to manage the oil fund has never taken it over and was instead managing a small portion - about $800 million - of the central bank’s own reserves.

NIC said central bank veteran Yeszhan Birtanov, who had a role in setting up NIC and ran it from 2012 to 2014, has replaced Otemurat at the management firm. (Reporting by Olzhas Auyezov, editing by Larry King)