Barry Callebaut, Nestle and Hershey's have all noted these trends following recent studies suggesting the health benefits of dark chocolate with a high percentage of cocoa.
Mars will be launching dark chocolate covered peanut M&M's along with a range of fruit-flavoured chocolate M&Ms.
"We are delighted to continue to grow the M&M's brand by introducing the first fruit-flavoured M&M's while meeting the popular growing demand of dark chocolate," said Anibal Martini, M&M's global marketing director.
According to a report on the market by Packaged Facts, overall US chocolate sales are forecast to reach $18bn (€13.2bn) by 2011, up from $16bn (€11.7bn) in 2006, helped by the growing demand for premium chocolate.
Premium chocolate will account for 25 per cent of the market, mainly due to the reported health benefits of dark chocolate, according to Packaged Facts.
Researchers claim the high percentage of cocoa can help lower blood pressure and prevent cardiovascular disease.
One study suggested that a high intake of flavonoids, powerful antioxidants, delivers benefits to the cardiovascular system - and dark chocolate contains almost five times the flavonol content of apples.
In August, Nestle said it will launch a new range of products including a dark chocolate collection and dark discovery bars.
Barry Callebaut also said in August that it will release nine new chocolate ingredients on the market aimed at processors targeting the demand for functional foods with health benefits.
Lindt also said last week that its most successful product segments include those with dark premium chocolate, and that it is likely to continue focussing on this segment.