Citizens, which RBS has been looking to spin off for more than a year, said in its filing that the stock sale is it expects to raise roughly $100 million, though that number is likely just a placeholder intended to decide registration fees. Citizens did not disclose the number of  many shares to be sold or their price.

Based in Providence, R.I., Citizens manages about $122 billion in assets and operates 1,366 bank branches across a dozen states in New England, the Mid-Atlantic and the Midwest.

Citizens said in its filing that it will not receive any of the proceeds from the IPO and the shares in question will be offered by RBS, which bought Citizens in 1988 and has been planning to spin off part of its stake in the bank sometime this year. RBS has been under pressure to raise money after receiving a bailout during the financial crisis from the British government, which still owns more than 80 percent of the bank.

Morgan Stanley (MS) and Goldman Sachs (GS) are the lead underwriters for the IPO, while JP Morgan Chase (JPM) is joint bookrunner.