Bertelsmann open to increasing stake in Penguin Random House

* CEO says ball is in Pearson (Xetra: 858266 - news) 's court

* First (Other OTC: FSTC - news) -half EBITDA rises to 1.1 bln euros from 1 bln euros

* Hawkins (NasdaqGS: HWKN - news) ' "Girl on the Train" sells more than 4.5 mln copies

* Higher sales, EBITDA forecast for full year (Recasts on Penguin Random House, adds background)

By Harro Ten Wolde

FRANKFURT, Aug 31 (Reuters) - German media Group Bertelsmann will consider raising its stake in book publisher Penguin Random House, it said on Monday, now that shares in the joint venture with Pearson could come on the market.

Privately held Bertelsmann controls 53 percent of the publisher of bestsellers such as the Fifty Shades series and Lee Child's Jack Reacher thrillers, one of the so-called big four English-language book publishing companies.

Pearson and Bertelsmann committed to holding their shares for at least three years when the Penguin Random House venture was unveiled in October 2012 and each partner has the right of first refusal thereafter.

Pearson has sold the Financial Times and its stake in the Economist in recent months to concentrate on education, and analysts have said a sale of its 47 percent stake in the book publisher would be the next logical move.

"Publishing has always been at the heart of Bertelsmann and it always will be. We could imagine raising our stake in Penguin Random house in steps," Bertelsmann Chief Executive Thomas Rabe said.

He declined to elaborate, indicating that the ball is now in Pearson's court. "It (Other OTC: ITGL - news) is up to Pearson whether they want to sell or not," he said.

The Pearson stake in Penguin Random House could be worth about 2.5 billion euros ($2.8 billion), based on comparable valuations of rivals, potential cost savings and negotiating power with retailers such as Amazon.

BOOK SALES BOOST

Rabe was speaking to reporters after half-year results that had been lifted by book sales in the United States and Britain.

The German media group said that its books business was one of the main reasons for a rise in sales and core profit over the first six months of the year, along with television.

Sales were driven by Paula Hawkins' debut novel "The Girl on the Train", which sold more than 4.5 million copies. "Grey", the new book by Fifty Shades author E. L. James, sold more than 3.5 million print, audio and e-book copies in the United States and United Kingdom in its first two weeks after publication.

Bertelsmann's adjusted earnings before interest, tax, depreciation and amortisation (EBITDA) rose to 1.1 billion euros in the first six months of the year, against 1 billion euros a year earlier.

Rabe said the company still expects core profit and sales to rise this year.

Bertelsmann also holds the majority of broadcaster RTL Group (Other OTC: RGLXF - news) , which raised its full-year sales forecast last week after regaining market share in its core German TV business. ($1 = 0.8925 euros)

(Editing by Georgina Prodhan and David Goodman)