Adult fiction ebooks outsold hardcovers in 2011: survey NEW YORK (Reuters) - Electronic books more than doubled in popularity in 2011, with ebooks outselling hardcover books in adult fiction for the first time, according to a survey released on Wednesday. Net sales of e-books jumped to 15 percent of the market in 2011 from 6 percent in 2010, according to a report by the Association of American Publishers and the Book Industry Study Group. The groups compiled data provided by nearly 2,000 publishers. Total overall U.S. book market sales declined 2.5 percent to $27.2 billion in 2011 from $27.9 billion in 2010, the report said. While ebooks increased in strength, bringing in more than $2 billion in 2011, the majority of publishers' revenue still came from print books, with $11.1 billion in 2011. "We're delighted to see it (the report) affirm that the industry has remained steady, and has even grown in some areas, in what continues to be a challenging economic time and through such significant transformation," said Len Vlahos, executive director of the Book Industry Study Group, in an email. The publishing industry has been more upbeat recently about the growth of ebooks, but the industry has been fearful over the impact of Borders, once the second largest U.S. book retailer, liquidating its 40-year-old business in September, as well as the U.S. Justice Department suing Apple Inc and major book publishers in April over fixing ebook prices. Ebooks have been growing in popularity for the past several years, even after major publishers were initially slow to embrace digital formats. According to the report, in the adult fiction category, e-books accounted for 30 percent of total net publisher sales compared to a 13 percent share the year before. Adult fiction ebooks beat hardcovers for the first time, however the combined print formats including hardcover, trade paperback and mass market paperback still had more revenue than ebooks. "Ebooks have demonstrated unprecedented acceptance among readers but the various print formats remain dynamic as well, showing that consumers want options," Vlahos said. Blockbusters such as "The Hunger Games" helped the Children's Young Adult category increase 12 percent to a total of $2.8 billion, while religious books rebounded after a decline in 2009. And, as traditional major publishers such as the privately-held Macmillan Group fret over the strength of online retailer and publisher Amazon Inc, the report found that brick-and-mortar retail was still the biggest sales channel for publishers, representing 31.5 percent of total net dollars. However that was down 12.6 percent from 2010. As a comparison, online retailers represented 13 percent of total net dollars, but grew 35 percent from the year before. Reporting By Christine Kearney; editing by Patricia Reaney