Rupert Murdoch’s News Corporation has bought the Nashville-based Thomas Nelson, Inc., Christian publishers, reports Jeffrey A. Trachtenberg for the Wall Street Journal.

The purchase was made by News Corp.’s HarperCollins book publishers. No terms of the sale were disclosed, but “it comes nearly 18 months after an investor group led by private-equity firm Kohlberg & Co. acquired a majority of Thomas Nelson’s stock. In 2006 the Nashville-based publisher had gone private in a transaction valued at about $473 million,” reported Trachtenberg.

According to 2009 trade sales figures cited by Michael Hyatt, Nelson’s board chairman in his personal blog , HarperCollins had a 9.8 percent market share of the overall book market while Nelson had 3.2 percent. The merger would seem to boost HarperCollins from fourth place to second, behind Random House with a 17.5 percent market share. 

In that same blog, Hyatt said Nelson had 32.6 percent of the Christian book market — with HarperCollins’ Michigan-based Zondervan in second with 16.9 percent of the market share. The Nelson acquisition would seem to give HarperCollins 49.5 percent of the religious book market.

“HarperCollins gained considerable leverage in the religious books market in 1988 when it acquired Zondervan, a large religious publisher based in Grand Rapids, Mich.,” wrote Julie Bosman for the New York Times. She reported:

“Thomas Nelson adds further balance to our existing publishing programs,” Brian Murray, the president and chief executive of HarperCollins, said in a statement. “Its broad inspirational appeal is a good complement to Zondervan, which will continue to publish books consistent with its mission.”

Erin Crum, a spokeswoman for HarperCollins, said the company would publish books under both the Thomas Nelson and Zondervan programs. Thomas Nelson, she added in an e-mail, “will keep its presence in Nashville.” Mark Schoenwald, the president and chief executive of Thomas Nelson, said the acquisition was an “attractive strategic fit” for the company. Schoenwald was promoted to chief executive this year.

According to BookStats, a survey conducted by two major trade groups that was released in August, in 2010, overall sales in the religion market were $1.35 billion.

Thomas Nelson was founded in Scotland in 1798, has published books by Billy Graham, Richard Stearns and Max Lucado, as well as Heaven Is for Real, the blockbuster story of a Nebraska boy’s near-death experience and what he says he saw when he visited heaven. The book has been on the Times paperback nonfiction best-seller list for 49 weeks and is now in the No. 1 position.