“My goals are 100% in sync with those of the foundation,” Buffett, 90, said Wednesday in a statement that also announced he had reached the halfway mark in giving all of his Berkshire Hathaway Inc. shares to charity.

Buffett has contributed more than $27 billion of his own money to the charity over the past 15 years. He’s one of the Gates Foundation’s three board members, alongside Bill Gates and Melinda French Gates, who announced last month they’re splitting after 27 years of marriage. Buffett has no involvement in the endowment’s investment decisions, according to the foundation.

Mark Suzman, the foundation’s chief executive officer, told employees last month that he’s in talks to strengthen “the long-term sustainability and stability of the foundation.”

Suzman “is an outstanding recent selection who has my full support,” Buffett said in the statement, which didn’t mention the divorce.

Three trustees is an unusually small number for an organization of its size. The Ford Foundation, which is roughly a fifth the size of the Gates Foundation, has 15 members on its board. The Rockefeller Foundation, at a 10th the size, has no fewer than 12 at any time.

Suzman said last month that no decisions have been made about what future steps need to be taken, but added that Bill Gates and Melinda French Gates have “reaffirmed their commitment to the foundation and continue to work together on behalf of our mission.”

Buffett and Bill Gates have been longtime friends. Gates previously served on Berkshire’s board, Buffett’s conglomerate, and announced last year he would step down from that post. Berkshire’s CEO decided in 2006 to donate a bulk of his wealth to the Gates’s foundation in part because the pair does a “much better job” at running those charity operations than Buffett says he could.

Buffett’s note Tuesday also addressed the tax deductions gained by philanthropy. The billionaire investor has recently been criticized for paying little in taxes, according to an investigation from ProPublica using Internal Revenue Service data. Buffett reiterated that his $41 billion of contributions to five foundations has produced only about 40 cents of tax savings per $1,000 given.

“That’s because I have relatively little income,” Buffett said in the statement. “My wealth remains almost entirely deployed in tax-paying businesses that I own through my Berkshire stockholdings, and Berkshire regularly reinvests earnings to further grow its output, employment and earnings. The income I receive from other assets allows me to live as I wish.”

He said it’s “fitting” for Congress to periodically revisit tax policy for charitable contributions.

Buffett, Berkshire’s chairman and CEO, said in 2006 that he would distribute all of his shares of the company to charity. He said in Wednesday’s statement that his most-recent $4.1 billion distribution brought him halfway to that target.

“In June of 2006, I owned 474,998 “A” shares. Now, I own 238,624 shares, worth about $100 billion,” he said, with all of them destined for philanthropy.

“Please understand that these remarks are no swan song,” the billionaire investor said in the statement. “I still relish being on the field and carrying the ball. But I’m clearly playing in a game that, for me, has moved past the fourth quarter into overtime.”

–With assistance from Sophie Alexander and Pierre Paulden.