New Delhi, Jan. 24 : Prime Minister Manmohan Singh is `doing fine' as he has been taken off the ventilator after undergoing a successful coronary by-pass surgery to overcome multiple blockages to his heart.

Dr Ramakant Panda who led the team of doctors during Singh's surgery said, "The 76-year-old Prime Minister is doing fine now. He is conscious. He also met his family and congratulated all doctors. Ventilator has been taken off and he is breathing on his own. This is an important step."

Prime Minister''s personal physician, Dr K S Reddy informed that the doctors were expecting Singh to attend to some of the official duties after two weeks, most of his official duties after four weeks.

"He will be fully active and functional by six weeks or even before. He will be more active now," he said.

One reason why the Prime Minister opted for an immediate surgery was he wanted to be ready and fully active well before the elections, Dr Sampath Kumar, Head of the Cardio Vascular Department at the AIIMS said.

Last night, the redo (repeat) by-pass surgery on Prime Minister Dr. Manmohan Singh had been declared successful..

Dr. Singh had been transferred to the Intensive Cardiac Care Unit (ICCU) after the operation.

"The operation was successful and there is nothing to worry about. His condition is stable. He has been moved to the Intensive Cardiac Care Unit (ICCU)," doctors at All India Institute of Medical Sciences (AIIMS) had said.

The operation was carried out by a team of 11 senior cardiac specialists, and was led by Dr. Ramakant Panda, a highly reputed cardiac surgeon from the Mumbai-based Asian Heart Institute.

It lasted for more than seven hours. Dr. Singh was admitted into the AIIMS on Friday afternoon after he complained of chest pain and fatigue.

Dr. Singh had undergone a cardiac bypass surgery in 1990 in UK, and angioplasty in Delhi in 2004 in which stents were introduced in his arteries.

Grafts, which were used to bypass the diseased vessel on Dr. Singh 18 years ago, had once again started to narrow. (ANI)