Global banking giant Citigroup has been officially warned by the Financial Services Agency of Japan to improve its business practices after two computer based problems resulted in thousands of incorrect transactions.

According to Citigroup itself, the agency has issued a ‘Business Improvement Order’ to the lender in response to IT based processing problems that led to over 250,000 transactions on both consumer and corporate accounts being mis-recorded.

The mistakes apparently occurred between May 2 and 8, and involved both withdrawals and deposits not being correctly recorded. Citigroup says the problem occurred in the data processing and development center of a Singapore-based affiliate that provides support to Citibank Japan.

Citibank Japan added in a statement that it takes the business improvement order seriously and apologizes to all parties concerned. The US lender’s Japanese division will submit a comprehensive business improvement plan to the FSA by August 14.

The unfortunate Japanese development comes as Citigroup has reported increasing its income from continuing operations by 11% to $5.26 billion in the second quarter. Revenues improved by 10% over the same period.