Online shopping deals giant Groupon has posted a sound quarterly profit but saw its stock tumble nearly 20 per cent due to a disappointing forecast for the months ahead.

The Chicago-based firm reported a profit of $US28.38 million ($A27.10 million) on revenue that climbed 45 per cent to $US568.3 million in the quarter ended June 30.

“We had a solid quarter despite challenges in Europe and continued investment in technology and infrastructure,” said Groupon CEO, Andrew Mason.

“We’ve deepened our relationships with a growing base of merchants and customers worldwide.”

However, investors were unhappy with revenue that was less than analysts expected and a scaled back forecast for the current quarter.

Groupon shares fell more than 20 per cent to a new low but regained some ground, down 18.41 per cent to $US6.16 in aftermarket trading on the Nasdaq.

The company made its stock market debut at $US20 per share in November and peaked above $US31 a share.

In February Groupon issued its first earnings report as a publicly traded company, saying it failed to turn a profit despite revenue nearly tripling from a year earlier.

Groupon shares were listed on the Nasdaq on November 4 in a blockbuster public offering that raised a whopping $US700 million and triggered fears that investors may be foolishly overvaluing hot internet startups.

Groupon, which rejected a $US6 billion takeover offer from Google a year ago, has enjoyed phenomenal growth since its founding in 2008 but has been dogged by questions about its business model and accounting methods.

AFP