Digital book sales accounted for 34% of Hachette Book Group’s adult trade sales in the U.S. during the first half of 2013, up from 27% during the same period last year. Hachette’s U.S. sales were up 7% during the period, which the publisher attributed to the film release of Nicholas Sparks books.

Hachette Book Group’s parent Lagardère released its half year sales figures today. Net sales amounted to about $1.2 billion, up 1.4% in reported terms from last year. Overall the Hachette Livre division is seeing growth in the digital category. Digital now represents 11.3% of total net sales for Hachette Livre, up from 8.4% for the same period in 2012.

HBG also had 35 eBook titles on the New York Times bestseller list in the first half of the year.  We had 29 #1 titles, a 70% increase over the same period last year.