Having spent two years creating a system that tracks and verifies e-book sales, the New York Times is to publish e-book best-seller lists, one for in fiction and another for non-fiction, starting early next year.

The New York Times' best-seller lists, widely considered the industry standard, were established in 1935. 

Janet Elder, the editor of news surveys and election analysis for The Times, said:

"We've had our eye on e-book sales since e-books began. It was clear that e-books were taking a greater and greater share of total sales, and we wanted to be able to tell our readers which titles were selling and how they fit together with print sales."

E-book sales have risen steeply in 2010. According to the Association of American Publishers, which receives sales data from publishers, e-book sales in the first nine months of 2010 were $304.6 million, up from $105.6 million from the same period in 2009, a nearly 190 percent increase.

Several major publishers said that e-books had climbed to about 10 percent of their total trade sales. Some publishing experts have predicted that they will rise to 25 percent in the next two to three years.

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