Rohatgi's appointment comes hours after the country's two top law officers Attorney General (AG) Goolam Essaji Vahanvati and Solicitor General (SG) Mohan Parasaran tendered their resignations on Wednesday following the change in the government at the Centre.
Since the tenure of law officers is co-terminus with that of the government, they tendered their resignations according to convention.
The law officers -- the AG, the SG and Additional Solicitors Generals -- represent the government in various courts and tender legal advice on complex issues.
Speculations were rife that senior advocates Mukul Rohtagi and Harish Salve were the front runners for the post of Attorney General.
According to a report, Rohatgi was the additional Solicitor General during Atal Bihari Vajpayee-led NDA government at the Centre and is considered to be very close to the Finance minister Arun Jaitely.
"Rohatgi is regarded as a ‘Master of Admission matters' in Supreme Court. He has the enormous ability to turn the judges in his favour with persuasive and practical arguments", the report further said.
On being asked, Rohatgi had said that he is "not reluctant to accept the constitutional post if offered".
Rohatgi is said to be "one of the country's highest paid lawyers", who has represented BJP-led governments in the Supreme Court many times.
Meanwhile, Ranjit Kumar is speculated to be the frontrunner for the post of Solicitor General.
Vahanvati was appointed AG in June 2009 after UPA came back to power. He was the Solicitor General for five years during UPA-1. In May, 2012 Mr Vahanvati was again appointed as AG till 2014 just before his three-year assignment as the top law officer of the country was coming to an end. He was the first Muslim to become the top law officer of the country.
In February last year, Additional Solicitor General Mohan Parasaran was elevated as the Solicitor General following the resignation of senior advocate Rohinton Nariman from the post. Mr Parasaran, a senior advocate of the Supreme Court and son of former Attorney General K Parasaran, was appointed as ASG by the first UPA government in July 2004.
(With agency inputs)