Mukesh Ambani does not do small. He is the richest man in Asia, chairman of India's biggest listed company, and lives in one of the largest and most expensive homes in the world.
On Monday, he struck a deal with BP that will see the British energy giant pump at least $7.2 billion into gas projects developed by his Reliance Industries in one of the country's largest foreign investments.
The blockbuster deal comes less than a year after Ambani won a gas pricing dispute with his younger brother Anil that went all the way to the Supreme Court, leading to the end of a long-running family feud that had captivated India.
At 53, Mukesh Ambani is the world's fourth richest man with a net worth estimated at $29 billion, according to Forbes.
The older son of Reliance Industries founder Dhirubhai Ambani, a schoolteacher's son whose rise inspired a Bollywood film, Mukesh is known to be soft-spoken, a vegetarian and a teetotaller, and keeps a lower public profile than his brother.
A chemical engineer by training, Mukesh Ambani dropped out of an MBA programme at Stanford University, where he was a classmate of Microsoft CEO Steve Ballmer, and joined Reliance in 1981.
After the death of their father in 2002, the two brothers fought publicly, ending with a split of the family business empire in 2005 that was brokered by their mother and saw Mukesh win control of energy-based conglomerate Reliance Industries.
Anil, now 51, took control of the telecoms, power and infrastructure businesses.
Mukesh Ambani has been an avid dealmaker.
Monday's deal with BP is expected to boost shares in Reliance Industries, valued at about $70 billion, company watchers said, as it brings in capital and technology.
Last year, he struck three shale gas joint ventures in the United States, including a $1.7 billion deal with Atlas Energy to own 40 % of its Marcellus Shale operations in the eastern United States.
Still, not everything he touches turns to gold.
Reliance bid $2 billion for 65 % of troubled Canadian oil sands company Value Creation but did not make it to the finish line. And its $14.5 billion offer to buy bankrupt petrochemicals maker LyondellBasell was rejected.
A father of three, Mukesh Ambani enjoys watching Bollywood movies in private screenings.
By comparison, Anil has been a regular on the social circuit with his wife, a former Bollywood actress.
Mukesh's wife, Nita, is trained in Indian classical dance and runs Mumbai's Dhirubhai Ambani International School, popular with the city's elite. She also co-owns the Indian Premier League cricket team Mumbai Indians, for which the Ambanis paid $111 million in 2008.
A member of Mumbai's prosperous Gujarati business community, Mukesh Ambani in 2010 said he would take a two-thirds pay cut after the Indian prime minister commented on "vulgar salaries."
But despite a staid image, Mukesh gave his wife a luxury private jet for her birthday in 2007.
Late last year he moved his five-member family -- and scores of servants -- into a $1 billion, 27-storey home, featuring three rooftop helipads, that towers over south Mumbai.
Monday's deal underscored his penchant for the big.
"Mukesh Ambani likes to play only on big platforms, and with this deal he has again shown the desire and hunger in him to take Reliance into a different paradigm," said Jagannadham Thunuguntla, head of research SMC Global Securities in New Delhi.