The three member commission is headed by Chile's UN Ambassador Heraldo Munoz. This was set up in Feb 2009 on the request from the Pakistani government.
Through a letter Secretary-general Ban Ki-moon has informed the Pakistani President, Asif Ali Zardari that the commission is set to start of the probe.
"The duty of determining criminal responsibility of the perpetrators of the assassination remains with the Pakistani authorities," Ban's spokesperson Michele Montas said.
The other two members of the commission are Marzuki Darusman, Indonesian former attorney general, and Peter Fitzgerald, a veteran of the Irish National Police.
The commission is expected to give in the report on the findings by six months to the secretary-general. And later Ban will share the report with the Pakistani government and submit it to the Security Council.