American billionaire Warren Buffett has once again auctioned off a private lunch and this time the highest bidder has agreed to pay over $3.4m (£2.4m) for the meal, with the proceeds going to a San Francisco homeless charity. The philanthropist has so far raised over $20m for the Glide Foundation.

The bid of $3,456,789 ties with the record highest bid in 2012, when a bidder agreed to pay the same amount, thereby becoming the most expensive individual charity item ever sold on eBay.

Six of the last eight winners paid more than $2m to dine with Buffett, one of the most successful investors in the world leading the Berkshire Hathaway conglomerate.

Each year, Buffett auctions off an invitation to lunch on eBay. The proceeds from the auction go to the Glide Foundation, which he started raising money for after his first wife Susie, who died in 2004, introduced him to the charity she had been volunteering for.

Last year's auction was won by Beijing-based Dalian Zeus Entertainment Company for $2.3m.

Buffett has praised the charity for running several anti-poverty programmes in San Francisco by providing meals, health care, jobs training, rehabilitation and housing support to the poor and homeless.

"I am proud to be part of something that has directly benefitted so many people in need," Buffett said ahead of the auction. "Glide is a bridge for thousands of people on the brink of despair, helping them achieve dignity and opportunity by providing them with basic services," the AP reported.

Speaking after the auction, which began on 5 June and wrapped up on Friday (10 June) night, Reverend Cecil Williams, one of the charity's co-founders, said: "We are astonished by the results of this year's auction and send heartfelt gratitude to Mr Buffett for his deep investment in unconditional love and community."

The lunch sessions with the philanthropist is said to usually run for a couple of hours, during which he generally speaks on any topic. However, the only limit on conversation is Buffet's future investment plans.

The winners of the auction are usually seen dining with the investor at Smith and Wollensky steak house in New York City, unless the winner wishes to maintain anonymity.