Apple chief executive Steve Jobs has blasted teachers unions at a US education reform conference.

Reports from the Associated Press said Jobs claimed head teachers were unable to improve schools because they can't fire bad teachers due to tenure. He also compared schools to businesses with principals serving as chief excutives.

"What kind of person could you get to run a small business if you told them that when they came in they couldn't get rid of people that they thought weren't any good?" he asked to loud applause.

Jobs said he saw future education, where a free online information source constantly updated by experts, much like the online encyclopedia Wikipedia would replace textbooks.

"I think we'd have far more current material available to our students and we'd be freeing up a tremendous amount of funds that we could buy delivery vehicles with - computers, faster Internet, things like that," he said. "And I also think we'd get some of the best minds in the country contributing."

Appearing with Jobs in a panel discussion, Dell Computer founder Michael Dell said schools should look to the corporate example, "where they take good care of their people. The employees won, they do really well and succeed."