MUMBAI - Mukesh Ambani, India's richest man, is faced with a prospect he has only rarely encountered: not getting what he wants.

After months in pursuit of LyondellBasell, Ambani's Reliance Industries appears set to fall short in a takeover bid valuing the petrochemicals group at $14.5 billion. Instead, Luxembourg-based Lyondell is poised to file a reorganization plan that may lead it out of bankruptcy.

Ambani, whose net worth was estimated at $32 billion by Forbes in November, is likely to treat this as a small setback in his quest to build a presence outside India, where his conglomerate is the biggest listed company and his family stands alongside the Tata clan at the pinnacle of the corporate elite.

Mukesh Ambani, 52, is the eldest son of Reliance's late founder Dhirubhai, a school teacher's son whose rise from the western state of Gujarat inspired a Bollywood film.

Media-shy, Mukesh Ambani nonetheless makes headlines for his ongoing feud with billionaire brother Anil, as well as the 27-story $1 billion home he is building that towers over an old-money neighborhood in South Mumbai.

But it is his stewardship of Reliance, which is engaged in petrochemicals, refining, oil and gas exploration, and textiles, where Ambani has made his mark, and he is expected to continue looking overseas after raising a warchest by selling $2 billion in company stock.

Despite his public reticence, Ambani clearly thinks big.

In late 2008, he commissioned a new 580,000 barrel per day (bpd) refinery next to Reliance's 660,000 bpd facility in Gujarat, creating the world's single-largest refining complex.

His overseas quest is driven in part by a search for crude oil to feed the refinery.

FAMILY TIES

Ambani joined Reliance in 1981 and took over the reins after his father died in 2002. A chemical engineer by training, Ambani dropped out of the MBA program at Stanford University, where he was a classmate of Microsoft CEO Steve Ballmer.

The family business has been the source both of wealth and of heartache for Ambani, who has been embroiled in a high-profile battle with younger brother Anil since 2004.

The latest dispute between the Ambani brothers is over details of a gas-supply deal -- part of a 2005 agreement brokered by their mother Kokilaben under which the Reliance group was split following the death of their father.

While Mukesh took over the energy and petrochemicals operations of the group, Anil emerged with the telecoms and power businesses.

The spat over the gas supply deal is tied-up in courts and saw Anil Ambani wage a very public campaign that included buying front page newspaper ads asserting that India's petroleum ministry was taking the elder brother's side in the dispute.

Last year, Ambani declared a surprise 1-for-1 bonus share issue, endearing him to Reliance stockholders. Around the same time, he said would take a two-thirds pay cut, days after comments by government officials over vulgar salaries.

PERSISTENCE

Known as the bada bhai -- meaning elder brother in Hindi -- the father of three enjoys watching Bollywood movies in private screenings, dresses unassumingly, and has earned a reputation for persistence in the boardroom and beyond.

In January, Ambani won a fierce bidding war for West Indian cricketer Kieron Pollard, offering $750,000 for the all-rounder to play as part of his Mumbai Indians cricket team in the third edition of the Indian Premier League Twenty-20 tournament.

His $100 million cricket franchise also includes star Sachin Tendulkar, the world's highest scoring batsman, and he has found other ways to splurge.

He gave a luxury jet with showers and a bar to his wife as a birthday present. Nita Ambani is a trained Indian classical dancer who also runs Mumbai's Dhirubhai Ambani International School, which is popular with the city's jetset.

A teetotaller, Ambani belongs to the Gujarati community noted for its business acumen.

He recently faced the wrath of a radical regional Hindu group in Mumbai for saying the city belonged to all Indians. Ambani has remained unruffled and appears unlikely to retract his comment.

(Editing by Tony Munroe and Lincoln Feast)