Sales at Hachette Book Group USA fell 4.2% in the third quarter ended September 30, compared to the same period last year. Parent company Lagardere attributed the decline to lower e-book sales and a stronger publication schedule last year. E-book sales accounted for 24% of HBG USA trade sales in the nine month period of 2015, down from 28% in the January-September period of 2014.

In prepared remarks, HBG USA CEO Michael Pietsch said soft e-book sales in the quarter were somewhat offset by the "excellent performance of downloadable audio and our distribution business."

The weak e-book sales numbers from Hachette follow similar reports last week from two other Big Five houses. Both HarperCollins and Simon & Schuster, in their recent quarterly reports, said e-book sales were down in 2015.

Aside from softening digital sales, HBG USA faced other difficulties over the last nine months. Before it announced the decline in the third quarter, revenue was down 7.8% in the first half of 2015 compared to last year. Nonetheless, Lagardere expects its American subsidiary to have a much better fourth quarter.

Pietsch said the fourth quarter "has started strong" and cited a long list of bestselling authors with new books coming out, including James Patterson, David Baldacci, Michael Connelly, Stacy Schiff, Robert Galbraith, Elin Hilderbrand, Stephenie Meyer, Peggy Noonan, and Douglas Preston & Lincoln Child.

Total revenue at Lagardere Publishing rose 7.8% in the third quarter, led by acquisitions in the U.K. and the positive effect of exchange rates. Excluding acquisitions and currency fluctuations, publishing sales would have been up 2.0%. Revenue in the most recent quarter was 607 million euros. Total e-book sales fell in the quarter and accounted for 7.9% of all revenue, down from 8.9% in last year’s third period.

In addition to soft e-book sales in the U.S., e-book revenue also fell in the U.K. and accounted for 30% of adult trade revenue in the nine month period, down from 34% a year ago. Despite the drop in e-book sales, overall revenue in the U.K. rose 1.2% due to a good performance in education and strong sales of adult coloring books.

For the nine month period, revenue at Lagardere Publishing increased 7.4% (down 1% excluding acquisitions and currency), to 1.58 billion euros.