NEW DELHI, Sept 18: The Mumbai terror attack convict Ajmal Kasab has formally pleaded for mercy and his petition has been sent to the President's office, the United News of India said, quoting prison authorities in Mumbai where he is lodged.

Last month, India's Supreme Court rejected a plea by Kasab, the only terrorist caught alive during the 26/11 Mumbai terror attack in 2008, to commute the death sentence handed to him by the Bombay High Court to life imprisonment.

Kasab had moved the Supreme Court on Feb 14, against the High Court verdict of Oct 10, last year, which upheld a lower court order sentencing him to death.

The lower court had pronounced its judgement on May 6, 2010, 18 months after Kasab was wounded and captured in the shootout.

More than 160 people were killed in the 2008 Mumbai attacks when 10 Pakistan-based terrorists sailed from Karachi to Mumbai.

Mercy petitions for presidential pardon have been pending for years for a host of convicts, including Afzal Guru, the Kashmiri man sentenced to death for the 2001 attack on the Indian parliament.