A unit of Citizens Financial Group recently reported a full-year net loss of $600.4 million for 2009 after charging off more than $2 billion in bad loans.

RBS Citizens, the No. 2 retail bank in Massachusetts, disclosed the loss in a financial report filed with the Federal Deposit Insurance Corp. The bank was not available to comment for this story.

With about $117 billion in assets, RBS Citizens accounts for most of the operations under the umbrella of Citizens Financial Group, a Providence, R.I.-based holding company with about $151 billion in total assets. Citizens Financial is owned by Royal Bank of Scotland Group plc, which also owns CharterOne Bank in the Midwest.

RBS Citizens set aside nearly $2.5 billion for anticipated loan losses in 2009. And during the year, the unit charged off $2.2 billion in bad loans. The bank has been hit hard by soured residential mortgages and commercial loans, FDIC filing show.

Deposits at RBS Citizens totaled $72.8 billion at the end of 2009. That compared with $74.2 billion at the end of the third quarter, FDIC filings show.