Washington  - Disgraced financier Bernard Madoff pleaded guilty in court Thursday to a 50-billion-dollar fraud that entwined hundreds of investors around the world and has made him the poster- child of Wall Street greed in the current financial crisis.

Madoff pleaded guilty to all 11 counts of fraud, telling the lower Manhattan federal court that he was "deeply sorry and ashamed," according to broadcaster CNBC. Judge Denny Chin is expected to accept the guilty plea before deciding whether Madoff can post bail or be remanded into custody while he awaits sentencing.

Madoff's lawyer Ira Sorkin on Tuesday said the investor would plead guilty after failing to reach a plea deal with prosecutors. The 70-year-old investor has been under house arrest since January at his Upper East Side Manhattan home on 10 million dollars bail.

The Federal Bureau of Investigation has estimated Madoff could face up to 150 years in prison. He faced criminal counts including securities fraud, mail fraud, wire fraud, three counts of money laundering and filing false statements with the Securities and Exchange Commission (SEC).

Madoff was arrested in December for allegedly running a 50- billion-dollar pyramid "Ponzi" scheme, under which he paid handsome dividends to investors over 20 years by continually collecting fresh funds from new clients.

His victims included celebrities, charities, universities and individual investors around the world. (dpa)