American Depositary Shares of the Shanghai-based company fell 41 cents, or 4.3 percent, to $9.24. The stock has traded between $20.46 and $8.46 since Giant began trading publicly in November.

Late Wednesday, Giant said it earned 20 cents per ADS, which analysts polled by Thomson Reuters expected.

The company cited changes it made in July to the revenue model for its flagship game, "ZT Online," as the reason for not giving guidance.

In a client note, Roth Capital Partners analyst Adam Krejcik downgraded the stock to "Hold" from "Buy" and lowered his 2008 and 2009 estimates for Giant.

"While we think Giant has the ability to 'right the ship,' given our expectations for a challenging 2H08 and lackluster pipeline we no longer feel comfortable recommending shares of Giant," he said.

Meanwhile, U.S. shares of Shanda Interactive Entertainment Ltd., which is also based in Shanghai, dipped 8 cents to $26.55.

In a client note, Goldman Sachs analyst Leah Hao predicted the company's second-quarter results will be in line with its outlook for up to 5 percent sales growth quarter-over-quarter and an operating margin of 37 percent to 40 percent. Shanda is slated to report on Wednesday.

The analyst thinks Shanda's third-quarter guidance will be seasonal and higher than in the second quarter but accounting for a negative impact from the Beijing Olympics.

Hao rates the stock "Neutral" with a $41 price target.

Elsewhere in the sector, U.S. shares of The9 Ltd., which is located in Shanghai and operates the popular game "World of Warcraft" in China, fell 23 cents to $18.40.

Beijing-based Netease.com Inc.'s U.S. shares fell 16 cents to $26.39.