It also plans to use at least 10 percent recycled materials for glossy titles such as cookbooks and art books by 2008.

The measures would equate to the preservation of more than 550,000 trees a year, Random House said.

Tyson Miller, program director of the Green Press Initiative which campaigns for more recycling, said Random House was the first major US publisher to make such a big commitment, though around 100 small companies had already moved over to recycled paper.

The company said the initiative would be a "multimillion-dollar investment" but did not give a specific figure.

"It's balancing what's environmentally right with practical publishing economics," Random House spokesman Stuart Applebaum said, adding that raising the figure even further would depend on the quality and quantity of recycled paper available.

Miller said the standard for major publishers was around 5 percent recycled paper. "Our hope is that Random House's example will pull in the other major multinational publishers," he said.

According to one estimate, switching to more recycled paper could raise the price of producing an average book by 3 cents, Miller said.

The 30 percent target will apply to more than 90 percent of the 120,000 tons of paper for book production that Random House purchases every year, the company said.