Nissan Motor has reported a 4.5% increase in second-quarter profits, citing strong sales of new car models launched last year as a major factor behind the improvement. Strong sales in North America helped to offset weak demand in Japan and the effects of a weak dollar. Nissan's net profit of 123.2 billion yen ($1.11 billion) for the April-June quarter was up from 117.89 billion yen a year earlier.