Charlie Munger, the longtime friend and business partner of famed US investor Warren Buffett, died on Tuesday at the age of 99, his employer has confirmed.

Berkshire Hathaway, where Munger served for decades as vice chairman under Buffett, announced it was "advised by members of Charlie Munger's family that he peacefully died this morning at a California hospital."

"Berkshire Hathaway could not have been built to its present status without Charlie's inspiration, wisdom, and participation," Warren Buffett said in a statement. 

Like Buffett, Munger was born and brought up in Omaha, Nebraska. The two met as adults in 1959 and forged a friendship that lasted more than 60 years. 

Munger joined Buffett at Berkshire Hathaway as vice chairman in 1978 and helped transform it from a small textile company into a gigantic conglomerate, now valued at more than $780 billion.

Unlike Buffett's vast fortune, Charlie Munger's wealth is estimated at a more modest $2.6 billion, although he has donated most of his wealth to charity during his lifetime. 

Munger never officially retired from his role at Berkshire Hathaway, and would have turned 100 on January 1, 2024. 

In a 2017 interview, Buffett credited Munger with changing his views on investment for the better. 

"He refined them in a huge way, in terms of looking for the quality companies, and looking out for the ability to make an investment that will work out for five or 10 or 20 years, as opposed to something where there might be one more puff left in the cigar," he said. 

"He's strong-minded, I'm strong-minded. We've never had an argument in that whole time and we never will," he continued. 

"It's been more fun doing it with Charlie," he added.