Facebook CEO Mark Zuckerberg and his wife Priscilla Chan celebrated the birth of their daughter Max with a promise to give 99 percent of their Facebook shares to a new charity. The couple announced the move in a letter addressed to their baby. (Reuters)

Facebook chief executive Mark Zuckerberg announced Tuesday he plans to eventually donate 99 percent of the Facebook stock owned by him and his wife Priscilla Chan, shares that are worth about $45 billion today, making it one of the largest-ever philanthropic commitments.

Zuckerberg said in an open letter that the birth last week of their first child — a daughter named Max — was the motivation to dedicate their considerable wealth to charitable causes now. They wrote they did not want to wait to “advance human potential and promote equality for all children.”

“I will continue to serve as Facebook’s CEO for many, many years to come,” Zuckerberg wrote, “but these issues are too important to wait until you or we are older to begin this work.”

The money will be channeled into the Chan Zuckerberg Initiative, a newly formed group that will initially focus on education and health. It was also clear from Zuckerberg’s letter that he and his wife had learned lessons from their earlier philanthropic attempts and plan to move in a new direction.

Zuckerberg’s announcement stands out because of his relative youth — he’s just 31 — and the gift’s massive size. The donation also comes at a time when the world’s wealthiest business leaders seem to be challenging each other to give away their fortunes before they die. Just a few days ago, Zuckerberg joined Bill Gates and a number of other tech titans to boost clean-energy and climate research.

In 2010, Gates and Warren Buffett publicly launched the Giving Pledge to encourage billionaires to donate the bulk of their wealth to charity. Gates, the former Microsoft leader, already has given away $31.5 billion, mostly to the Bill and Melinda Gates Foundation. Buffet has given away more than $22 billion of his Berkshire Hathaway stock and plans to eventually donate nearly his entire fortune.

More than 130 billionaires worldwide have joined them, including Judy Faulkner, founder of electronic health records company Epic, who reportedly said she plans to give away 99 percent of her money. Also this year Saudi Prince Alwaleed bin Talal, one of the richest men in the world, , said the pledge inspired him to eventually give away his entire fortune, more than $30 billion.

Zuckerberg quietly committed weeks ago to this pledge too, although his Nov. 9 Giving Pledge letter didn’t reveal the scale of his intentions.

A federal filing shows the Facebook co-founder will start by giving away up to $1 billion a year in Facebook stock for the first three years. Such tax-efficient arrangements are not unusual for gifts to private foundations.

"He clearly wants to be perceived as a leader of his generation in the same way as Buffett and Gates are theirs," said Richard Marker of the New York advisory firm Wise Philanthropy.

The couple revealed their plans in a lengthy “letter to our daughter” published on Facebook, the social network Zuckerberg co-founded while a student at Harvard and which today has 1.5 billion monthly active users worldwide.

Their daughter’s full name is Maxima Chan Zuckerberg, and she was born just before Thanksgiving, weighing 7 pounds, 8 ounces, according to a Facebook spokeswoman.

In the open letter, Zuckerberg and Chan talked about the potential that technology offers to re-engineer the way children learn.

“Our generation grew up in classrooms where we all learned the same things at the same pace regardless of our interests or needs,” they wrote.

Zuckerberg and Chan have given $15 million to AltSchool, a for-profit corporation founded by a former Google executive working to create a network of schools that use technology to personalize instruction. The couple also has given $120 million to traditional public schools and public charter schools in the San Francisco Bay Area.

But Zuckerberg’s first foray into education philanthropy was in itself a learning experience. In 2010, he gave $100 million to remake public schools in Newark, N.J., with mixed results.

Critics of that effort said the plan faltered in part because it was a top-down approach that called for wholesale changes in the city’s public schools with plans crafted by outsiders, not community members.

In their letter to Max, Zuckerberg and Chan talked about the value of learning from mistakes.

“Your mother and I have both taught students and we’ve seen what it takes to make this work,” the couple wrote. “It will take working with the strongest leaders in education to help schools around the world adopt personalized learning. It will take engaging with communities, which is why we’re starting in our San Francisco Bay Area community.”

Zuckerberg and Chan, a pediatrician and onetime teacher, plan to open a private, tuition-free school for low-income children in East Palo Alto, Calif., that will integrate health care and support for families with classroom learning.

While the letter to their daughter Max was obviously intended for a much wider audience, revealing their ambition to fund billions of dollars in new philanthropic works, the couple ended their note in a more personal, quiet fashion.

It was signed simply, “Love, Mom and Dad.”