* CSI300 -2.4 pct; SSEC -2.4 pct; HSI -0.4 pct
* Investors ignore better-than-expected Q2 GDP data
* Small caps set to end four-day winning streak
SHANGHAI, July 15 (Reuters) - China stocks fell early on Wednesday, as the market's rebound from last Thursday prompted heavy selling in spite of better-than-expected economic data.
Small caps led the decline after four consecutive sessions of gains, but banking shares were firmer following the previous day's losses.
The CSI300 index fell 2.4 percent, to 4,012.25 points at the end of the morning session, while the Shanghai Composite Index lost 2.4 percent, to 3,830.49 points.
Stocks also fell in Hong Kong, with the benchmark Hang Seng index dipping 0.4 percent.
After plunging by a third since mid-June, the mainland market has stabilised following a slew of government measures aimed at stemming the free-fall.
"The government has done its job, and the market is going back to its own tempo," said Qi Yifeng, analyst at CEBM Group Ltd.
Better-than-expected Chinese economic data on Wednesday had little impact on sentiment.
"Investors were awaiting further hints for direction and anticipating new stimulus from the government," said Steven Leung, a director at UOB Kay Hian in Hong Kong. "They liquidated their positions as the GDP data failed to impress while domestic consumption showed no sign of improvement."
China's economy grew an annual 7 percent in the second quarter, slightly better than analysts' forecasts.
"Stock investors for now care more about government policy towards the market...whereas the connection between the economy and the market has somehow been loose," said Zhang Qi, analyst at Haitong Securities in Shanghai.
As the market stabilises, Chinese regulators are starting to deal with the roots of the boom and bust, launching a fresh crackdown on grey-market margin financing.
But on the upside, China Asset Management Co and Harvest Fund Management Co each set up a 40 billion yuan ($6.44 billion) fund on Tuesday after a one-day flash-funding, stirring speculation that fresh government money was entering the market.
Some observers remained pessimistic about the outlook.
Independent research company Capital Economics said: "Q2's stronger-than-consensus GDP growth partly reflects an unsustainable surge in financial sector activity that will prove short-lived."
U.S.-based, China-focused consultancy JL Warren Capital also held a bearish view. The question is "whether the onshore stock market has bottomed. We think it is unlikely," it wrote in a comment on China stocks.
"Over the next 6-12 months, we expect to see the onshore stock market converging to the pre-rally level, as a slew of worse-than-expected macro data and corporate earnings roll out."
Shenzhen's start-up board ChiNext lost 2.9 percent. Infrastructure, transport and health care stocks also fell sharply.
In Hong Kong, the Hang Seng index dropped 0.4 percent, to 25,018.72 points, while the Hong Kong China Enterprises Index lost 1.0 percent, to 11,723.19. (Reporting by Samuel Shen and Pete Sweeney; Editing by Jacqueline Wong)