Popular legal thriller author John Grisham has broken his holdout against selling his books in an electronic format and will sell all of his 23 titles as e-books, his publisher said on Tuesday.

The former lawyer, whose best sellers include The Firm and A Time To Kill, had previously held off selling his books electronically, expressing concern that e-books would wipe out traditional book stores and make it harder for new writers to succeed.

But beginning Tuesday, all Grisham's fiction and non-fiction books will be available through e-book retailers, publisher Random House said.

As e-books have grown in popularity, some authors have been embroiled in royalty negotiations with publishers. Publishers in turn have had disagreements with e-book retailers such as Amazon.com about how to split e-book sales.

Stuart Applebaum, a Random House spokesman, would not disclose the terms of the deal, but said today was a watershed deal.

The deal is certain to usher in a new generation of Grisham readers and e-book adopters, Sonny Mehta, chairman of the Knopf Doubleday Publishing Group, which is owned by Random House and publishes Grisham's hardback titles, said in a statement.

Since his first novel A Time To Kill was released in 1989, Grisham has sold more than 250 million books worldwide, according to Random House. Several of his novels have been turned into films.

Grisham's literary agent said the author had no comment on Tuesday's announcement.

Grisham said in a TV interview last November that discounting of printed books by major retailers and the advent of e-books was a disaster in the long term for publishers, bookstores and authors.

If a new book is now worth about $9 then we have seriously devalued that book, Grisham said on the Today show.

Suddenly the whole industry is going to change, you are going to lose publishers, you are going to lose bookstores. I am probably going to be alright, but the aspiring writers are going to have a hard time getting published, he added.

Grisham's e-books were available on Tuesday through e-book retailers such as the Sony Reader Store, Barnes & Noble.com and Amazon.com, who all had Grisham's newer print editions like The Associate listed at $9.99 and his older books at $7.99.

According to statistics released by International Digital Publishing Forum, wholesale revenue from e-book sales in the United States more than tripled in the fourth quarter of 2009 to $55.9 million from $16.6 million in the same quarter in 2008.

(Reporting by Christine Kearney, editing by Jill Serjeant)