Utahns Jon Huntsman Sr. and wife Karen are among 40 wealthy families and individuals who have joined Microsoft Corp. co-founder Bill Gates and billionaire investor Warren Buffett in a pledge to give at least half their wealth to charity.

Six weeks after launching a campaign to get other billionaires to donate most of their fortunes, Buffett, the chairman and CEO of Berkshire Hathaway Inc., released the first list Wednesday of people who have signed what he and Gates call the "giving pledge."

Huntsman said he and Buffett have been friends for years.

"I told him, when he asked if I'd donate 50 percent of my assets to charity, that I was already doing that. I said, 'I'll be happy to sign the pledge, Warren, but I want you to do know I've already done that long before you called, and it has not only been 50 percent but 80 percent, and the other 20 percent will follow!"

Huntsman said that over his lifetime, he's given $1.2 billion to charitable organizations. "That represents today about 80 percent of our net worth," he said.

Huntsman said most of that, about 75 percent, has gone to Utah. "We've given to colleges and universities throughout Utah, and to the University of Pennsylvania, and have tried to advance higher education in the U.S. and abroad, and we've worked to relieve homelessness here and abroad, as we did in building homes and a school in Armenia after the earthquake. And, of course, the greatest portion was committed to Huntsman Cancer Institute, but we enjoy supporting many other charitable causes."

Buffett decided in 2006 to give 99 percent of his fortune to charity. Then, he was worth about $44 billion. After five years of investment returns while making annual gifts to five foundations, Buffett's fortune totals nearly $46 billion.

Bill and Melinda Gates do most of their philanthropic giving through their foundation, which had assets of $33 billion as of June 30 and has made at least $22.93 billion in total grant commitments since 1994.

Buffett said he, the Gateses and others have made 70 to 80 calls to some of the nation's wealthiest individuals. The people who agreed to the pledge are from 13 states, with the most participants in California and New York.

Among those who haven't signed the pledge, some prefer to keep their philanthropy anonymous, some were not available to talk and others were not interested, Buffett said.

Many on the list will be asked to call others, and small dinners will be held across the country in coming months to talk about the campaign.

"We're off to a terrific start," Buffett said.

Buffett said he and Bill Gates also will meet with groups of wealthy people in China and India within the next six months to talk about philanthropy. They hope the idea of generosity will spread, but they have no plans to lead a global campaign, Buffett said.

Gates and Buffett estimate their efforts could generate $600 billion dollars in charitable giving.

Huntsman said he told Buffett, "Warren, it's nice that you're officially asking people to do this, but I would hope that most would have done it years ago and wouldn't need to be asked. I would hope that most who have amassed great wealth would take it upon themselves as good citizens to help mankind and to assist their fellow citizens without any prompting from you or Bill Gates!'

"He said, 'People like you, Jon, have done that instinctively, but not many others do it that way.' "

In 2009, American philanthropies received a total of about $300 billion in donations, according to The Chronicle of Philanthropy.

Stacy Palmer, editor of The Chronicle, was surprised and impressed by the speed at which the giving pledge idea has been accepted.

"I think it's remarkably fast that so many people went public with their commitments. The world of philanthropy tends to be very slow moving," she said.

Palmer noted that many of names on the list are people who are known for their philanthropic generosity. She said she would be more excited when she sees names that have not been on other major donor lists.

Taking the idea past billionaires toward millionaires and regular working people could make an even bigger impact, Palmer added.

Jason Franklin, executive director Bolder Giving, a relatively new organization that encourages big gifts from everyday people, agreed.

The Bill & Melinda Gates Foundation gave Bolder Giving a $675,000 challenge grant earlier this year to encourage more people to give at least 20 percent of their personal wealth to charity.

Franklin estimates the giving power of the world's millionaires eclipses the potential donations from U.S. billionaires many times over.

Gates and Buffett are asking billionaires not just to make a donation commitment, but to also pledge to give wisely and learn from their peers.

Their group has no plans for combined giving, and none of the philanthropists will be told how or when to give their money.

"Everybody has their own interests," said New York Mayor Michael Bloomberg, who participated in a teleconference with Buffett on Wednesday as one of the individuals who has signed the giving pledge. "That's what's wonderful about private philanthropy."

Bloomberg, who has a fortune estimated by Forbes magazine at $18 billion, said he has changed his personal philosophy over the years from wanting to be more private about his giving toward trying to play a leadership role. He said his whole family is in tune with his giving plan.

"I've always thought your kids get more benefit out of your philanthropy than your will," he added.

Others who have signed the pledge include filmmaker George Lucas, media mogul Ted Turner and Microsoft co-founder Paul Allen.

Contributing: Deseret News staff

"Giving Pledge" list

 California

Eli and Edythe Broad

Michele Chan and Patrick Soon-Shiong

Ann and John Doerr

Larry Ellison

Barron Hilton

Joan and Irwin Jacobs

Lorry I. Lokey

George Lucas

Alfred E. Mann

Tashia and John Morgridge

Bernard and Barbro Osher

Herb and Marion Sandler

Jeff Skoll

Tom Steyer and Kat Taylor

 Georgia

Bernie and Billi Marcus

Ted Turner

 Hawaii

Pierre and Pam Omidyar

 Maryland/Washington, D.C.

David M. Rubenstein

Vicki and Roger Sant

 Michigan

Thomas S. Monaghan

 Missouri

Jim and Virginia Stowers

 Nebraska

Warren Buffett

Walter Scott Jr.

 New York

Michael R. Bloomberg

Barry Diller and Diane von Furstenberg

Elaine and Ken Langone

Ronald O. Perelman

Peter G. Peterson

Julian H. Robertson Jr.

David Rockefeller

Jim and Marilyn Simons

Sanford and Joan Weill

Shelby White

 Oklahoma

George B. Kaiser

 Pennsylvania

Gerry and Marguerite Lenfest

 Texas

Laura and John Arnold

T. Boone Pickens

 Utah

Jon and Karen Huntsman

 Washington

Paul G. Allen

Bill and Melinda Gates

Source: givingpledge.org