KILCHBERG, SWITZERLAND — Organic sales growth of nearly 13% in North America helped drive a 10% gain in overall sales and keyed a 40% increase in net income at chocolate maker Lindt & Sprungli AG in the first half of 2013 ended June 30.

Net income in the first half was 48.8 million Swiss francs ($53.1 million), up from 34.8 million Swiss francs in the first half of 2012. Sales increased to 1,132 million Swiss francs ($1,233 million) from 1,032.6 million.

Lindt & Sprungli said Lindt USA and Lindt Canada, along with Ghirardelli, contributed to the strong growth in North America during the first half. Elsewhere, Lindt & Sprungli said its main European markets of Germany, France, the United Kingdom and Switzerland also performed well. In Italy, where the chocolate market has felt pressure, Lindt & Sprungli maintained steady sales, the company said.

On the expansion front, the company said its recently opened subsidiaries in Russia, China and South Africa have successfully started with “accelerated development” in their respective markets.

Lindt & Sprungli confirmed its medium- to long-term strategic targets and forecasts for organic sales growth of 6% to 8%.