* Kazakhstan supports IBA debt restructuring plan
* Plans to swap into 15-year Azeri sovereign bonds
* Expects creditor vote by mid-July (Adds details, context)
By Mariya Gordeyeva
ASTANA, June 15 (Reuters) - Kazakhstan plans to support the debt restructuring plan proposed by state-run Azeri lender IBA, Kairat Kelimbetov, a board member of the Kazakh state pension fund, said on Thursday.
Kelimbetov told reporters the Central Asian nation planned to choose an option under which the IBA debt it holds would be exchanged one-on-one for 15-year Azerbaijan sovereign Eurobonds paying 3.5 percent.
"According to preliminary information, the voting (by creditors) will be called either today or tomorrow and take place before mid-July," he said.
Kazakhstan's central bank acquired 10-year bonds issued by the International Bank of Azerbaijan via private placement for its pension fund in 2014, when Kelimbetov was the chairman of the central bank.
But IBA's plan to restructure $3.3 billion of debt, including the chunk held by Kazakhstan, has sparked anger and led Kazakh authorities to launch an investigation into the purchase .
Kazakhstan is a close political ally of its ex-Soviet peer Azerbaijan and a source told Reuters that representatives of the central bank had been in touch with the IBA, but the Azeri side gave Astana no special treatment.
The notes held by the Kazakh pension fund would put it in the category of IBA creditors who are required to swap their holdings for longer-dated paper or take a writedown. (Reporting by Mariya Gordeyeva; Writing by Olzhas Auyezov; Editing by Subhranshu Sahu & Shri Navaratnam)