Facebook Inc Chief Executive Mark Zuckerberg and his wife Priscilla are seen with their daughter named Max in this image released on December 1, 2015.[Photo/Agencies]

Mark Zuckerberg will put 99 percent of his Facebook Inc shares, currently worth about $45 billion, into a new philanthropy project focusing on human potential and equality, he and his wife said Tuesday in a letter to their newborn daughter.

The plan, which was posted on the Facebook founder and chief executive officer's page and has attracted more than 360,000 "likes", follows other high-profile billionaires such as Warren Buffett and Bill and Melinda Gates, who have set up foundations to dedicate their massive fortunes to philanthropic endeavors.

Zuckerberg, 31, who will control the new initiative and remain in charge of the world's largest online social network, said he would sell or give up to $1 billion in shares in each of the next three years.

He will keep a controlling stake in Facebook, valued at $303 billion as of Tuesday's close, for what the company called the "foreseeable future." According to Facebook's most recent proxy statement, Zuckerberg owned 4 million Class A shares and 422.3 million Class B shares, which have 10 times the voting power of A shares. Combined he held 54 percent of the voting power of the company's shares.

Zuckerberg said he plans to remain CEO of Facebook for "many, many years to come."

The move is not Zuckerberg's first in the world of philanthropy. When he was 26, he signed the Giving Pledge, which invites the world's wealthiest individuals and families to commit to giving more than half of their wealth to philanthropy or charitable causes over their lifetime or in their will.

"Mark and Priscilla are breaking the mold with this breathtaking commitment," billionaire investor Buffett said on Facebook. "A combination of brains, passion and resources on this scale will change the lives of millions. On behalf of future generations, I thank them."

Buffett himself pledged Berkshire Hathaway Inc stock worth $31 billion at the time to Gates' foundation in 2006, which was the largest single gift at the time.

Zuckerberg is relatively young to commit so much of his wealth. Microsoft Corp co-founder Gates was 45 in 2000, the year he and his wife founded the Bill and Melinda Gates Foundation. Buffett was 76 in 2006, the year he committed to give away all of his Berkshire Hathaway stock to philanthropic organizations.