By Asit Jolly BBC correspondent in Chandigarh

Manmohan Singh's family are ecstatic about his forthcoming premiership

Mr Singh is the first Sikh and the second Punjabi to become prime minister of India after Inder Kumar Gujral.

Two of Mr Singh's younger brothers - Surjit Singh and Daljit Singh - and their sister Narinder Kaur said they were delighted at his success.

"This is far beyond our wildest dreams," Surjit Singh told the BBC.

Congratulations all round

Mr Singh's family dealt with a torrent of telephone calls from television networks in India and all over the world following his appointment as prime minister designate.

Many people in Punjab are proud of the incoming PM

The family immediately ordered several dozen boxes of sweets for the uninterrupted stream of friends and acquaintances that have been arriving to congratulate them.

"It is quite like a wedding in the house. We never thought this would ever happen!" Surjit Singh said.

Equally ecstatic about the unexpected turn of events were Mr Singh's former colleagues, who worked with him in university and in India's Planning Commission.

'Bicycle riding professor'

"We could not be happier and we are putting this down in a joint statement of felicitation," said Professor GS Bhalla who taught with Dr. Singh at the university in Punjab.

Describing the prime minister designate as "a man with unquestionable integrity and total commitment to his work," Professor Bhalla said that Manmohan Singh was more of a statesman than a politician.

"Even though this man is not used to playing political games, he will make a great prime minister with support from the Congress President Sonia Gandhi," he said.

"I believe Manmohan Singh will now bring in reforms but with a human face."

Another academic, HS Shergill, says he learnt about economics as a student of Dr Singh.

It is quite like a wedding in the house. We never thought this would ever happen!" Surjit Singh, sister of Manmohan Singh

He remembers him as "a very simple, bicycle-riding young professor, who was the centre of admiration on the Punjab University campus."

"He inspired many of us to abandon careers as prospective bureaucrats and instead pursue academics.

"He was a great teacher who had become something of a star to all of us well before the world recognised his excellence," Mr Shergill said.

"Manmohan Singh is a man who cannot be lured by anything but the prospect of glory by excelling at his own work.