Revenue for the first quarter ended March 31, 2016 fell 10.3% at Hachette Book Group, compared to the same period last year, parent company Lagardere reported.

Despite the sales decline, HBG CEO MIchael Pietsch said profits rose in the quarter. Pietsch said earnings rose because of "lower unearned advances and continued strong sales of HBG's downloadable audio."

The revenue decline was attributed in part to the release of fewer major hardcover titles, compared to the first period of 2015. E-book sales were also soft in the quarter. Lagardere reported that e-book sales accounted for 26% of HBG trade sales in the quarter, down from 28% in the comparable period last year. HBG is the fifth major trade house to report soft first quarter e-book sales.

Pietsch noted that HBG's purchase of the Perseus Books Group publishing arm was completed at the end of the quarter and that the process of integrating Persues's books and authors into Hachette has begun. He also pointed to the strong start of Hamilton: The Revolution, which has emerged as a major bestseller in the quarter. HBG expects to have 400,000 copies of the book in print by summer.

For the entire Lagardere publishing group, revenue fell 1.4% in the quarter to €415 million. Digital sales accounted for 10.4% of total revenue in the quarter, down from 12.2% a year ago.