The Top 8 Billionaires in the World-Part-III

3) Warren Buffett

Net Worth: $47 billion

Source: Investments

Residence: U.S.

• America's favorite investor up $10 billion in past 12 months on surging Berkshire Hathaway shares; says U.S. has survived economic "Pearl Harbor," but warns recovery will be slow.

• Shrewdly invested $5 billion in Goldman Sachs and $3 billion in General Electric amid 2008 market collapse.

• Recently acquired railroad giant Burlington Northern Santa Fe for $26 billion.

• "We've put a lot of money to work during the chaos of the last two years. When it's raining gold, reach for a bucket, not a thimble."

• Berkshire Hathaway book value was up 19.8% to $21.8 billion in 2009.

• Son of Nebraska stockbroker met value investor Benjamin Graham while studying economics at Columbia.

• Took over textile firm Berkshire Hathaway in 1965, used company as a vehicle to invest in insurance (Geico), food (Dairy Queen), utilities (MidAmerican Energy) and recently green tech (electric-car maker BYD).

4) Mukesh Ambani

Net Worth: $29 billion

Source: Petrochemicals, oil and gas

Residence: India

• Global ambitions: His Reliance Industries, already India's most valuable company, recently bid $2 billion for 65% stake in troubled Canadian oil sands outfit Value Creations.

• Firm's $14.5 billion offer to buy bankrupt petrochemicals maker LyondellBasell was rejected.

• Since September company has sold Treasury shares worth $2 billion to be used for acquisitions.

• Late father, Dhirubhai, founded Reliance and built it into a massive conglomerate. After he died, Mukesh and his brother, Anil, ran the family business together for a brief time. But siblings feuded over control; mother eventually brokered split of assets, with Mukesh getting oil, gas and petrochemicals businesses.

• Still at odds with Anil over gas supply agreement; awaiting Supreme Court's final ruling.

• Owns cricket team Mumbai Indians.