The Almaty-based bank filed late Thursday for protection under Chapter 15 of the U.S. bankruptcy code with the U.S. bankruptcy court in Manhattan.
The filing came a year after Kazakh's state-owned Samruk-Kazyna National Welfare Fund took a 75 percent stake in the bank.
BTA had struggled with increasing loan losses, a reduced ability to make loans and an inability to refinance its debt.
The bank controls about 18 percent of banking assets in Kazakhstan, court filings show. It had about $29 billion of assets before the nationalization, Standard & Poor's has said. Several other Kazakh banks have also had capital struggles.
Non-U.S. companies use Chapter 15 to block creditors who want to file lawsuits or tie up assets in the United States.
Most of BTA's assets are in Kazakhstan, and most of its U.S. assets are in New York City banks, court records show.
Anvar Saidenov, who is BTA's chairman and a former chairman of Kazakhstan's central bank, said in a court filing the bankruptcy filing was necessary because certain creditors have started to take action against the bank.
He said the bank is involved in litigation in Britain and Russia, and that a creditor has tied up some of its Switzerland accounts.
Saidenov said the bank expects to complete a roughly $12.1 billion restructuring in the third quarter of 2010, including $11.6 billion of debt and $529 million of interest.
He said creditors would receive a mix of cash, debt, equity and recovery notes in exchange for their claims.
The case is In re: JSC BTA Bank, U.S. Bankruptcy Court, Southern District of New York, No. 10-10638.
(Reporting by Jonathan Stempel; Editing by Derek Caney)