Citigroup Inc is on track to exceed expected regulatory requirements and shrink its worst assets to less than 20 percent of its balance sheet, Chief Executive Vikram Pandit told employees in an end-of-year internal memo on Monday.

The Treasury earlier this month sold its remaining shares in the Citigroup, ending a long and difficult chapter for the bank after it received $45 billion in three government bailouts during the financial crisis.

Like other U.S. banks, Citi -- which returned to profitability this year -- is also trying to grapple with new rules put in place to try and prevent a repeat of the crisis.

We believe we are poised to meet and exceed anticipated regulatory requirements, Pandit wrote in the memo.

The past three years have been challenging, but I believe we now have in place all the elements for sustained profitability and responsible growth, he later added.

The bank, which struggled amid mounting losses on credit cards and mortgages, has been selling some of its assets from its Citi Holdings unit. Citi last month sold a $1.4 billion real estate loan portfolio to OneWest bank, helping it shrink Citi Holdings to less than 20 percent of Citi's total balance sheet.

Citi shares were flat at $4.77 on Tuesday. The shares have climbed 44 percent since the start of the year.

(Reporting by Elinor Comlay; Editing by Bernard Orr)