Giant?Interactive Inc's net profit grew an annual 5.6 percent in the third quarter as more users paid to play games like ZT Online, the Nasdaq-listed firm said yesterday.

But its revenue was less than expected because of a drop in individual user's average spending.

In the third quarter, Giant posted a net profit of 208.7 million yuan (US$31.2 million).

It has generated a 16.7 percent annual jump in revenue to US$50.6 million in the same period - lower than analysts' expectations of US$51 million.

Giant's average revenue per user (ARPU), a key measure of profitability, fell 13.4 percent from a year ago to 225 yuan between July and September.

But the game firm saw a surge of 35.1 percent annually in its active paid user base to 1.49 million in the period.

Investment bank Morgan Stanley forecast Giant's revenue to grow rapidly in 2011 through new game titles.

"Thanks to new games, we expect its sales to accelerate 20 percent in 2011 compared with only 1 percent this year," it said in a note yesterday.