Microsoft Corp. founder Bill Gates today renewed his appeal to the world's billionaires to give up their fortunes to charitable causes.

But in Washington, the software giant’s chief executive, Steve Ballmer, made it clear that the company’s charitable views don’t extend to paying what it considers unfair U.S. tax rates: Ballmer threatened to move more jobs overseas if President Obama prevails with his proposal to end tax breaks on foreign earnings.

Maybe Ballmer is just thinking about how to make more generous billionaires out of Microsoft shareholders, if he can boost the bottom line enough to revive the stock as a genuine growth investment -- which it hasn't been since the 1990s.

Gates, who has used his Microsoft wealth to fund the $27-billion-asset Bill & Melinda Gates Foundation, told a gathering in Oslo that he believed that "all billionaires should give away the vast majority of their fortunes -- though I don't say they shouldn't leave anything to their kids."

From Reuters:

"I think they would enjoy it, their kids would be better off, and the world would be better off," Gates said. "I'm a great believer that great wealth should go from the richest to the poorest," he said, seated next to his wife, Melinda, who co-chairs the foundation.

Across the Atlantic, Ballmer said Microsoft would move more jobs overseas if Congress goes along with Obama’s proposed tax changes on foreign-derived earnings.

From Bloomberg News:

"It makes U.S. jobs more expensive," Ballmer said in an interview. "We’re better off taking lots of people and moving them out of the U.S. as opposed to keeping them inside the U.S." Obama on May 4 proposed outlawing or restricting about $190 billion in tax breaks for offshore companies over the next decade. Such business groups as the National Foreign Trade Council, the U.S. Chamber of Commerce and the Business Roundtable have denounced the proposed overhaul. U.S. tax rules now let companies defer paying corporate rates as high as 35% on most types of foreign profits as long as that money remains invested overseas. Obama says he wants to end such incentives.

Obama believes the changes would preserve U.S. jobs. Ballmer says it would have just the opposite effect.

-- Tom Petruno

Top photo: Bill Gates. Credit: Nelson Ching / Bloomberg News

Bottom photo: Steve Ballmer. Credit: Rajanish Kakade / Associated Press