* SSEC +0.1 pct, CSI300 -0.1 pct, HSI flat
* iVX, China's anxiety gauge, jumps to 4-month high
* Stock options trade hits record high
SHANGHAI, May 26 (Reuters) - China stocks held steady on Friday after a tumultuous week, with the Shanghai index holding above the key 3,000-point level even after Moody's downgraded the country's sovereign credit rating.
Thursday's surge in index-heavweight financial stocks on apparent government support, a day after Moody's cut the rating, continued to support market sentiment, traders said.
But iVX - dubbed China's anxiety gauge - has jumped to a four-month high, while trading in stock options hit record volumes, pointing to further volatility ahead.
After jumping more than 1 percent the previous session, both the blue-chip CSI300 index and the Shanghai Composite Index were roughly flat by midday, at 3,482.52 points and 3,110.74 points, respectively.
SSEC fell to as low as 3,022.30 on Wednesday following the downgrade. The gauge has since rebounded sharply, led by banking stocks.
"This is apparently stabilisation effort by the government. The index has dropped to a very critical level," said Wu Kan, head of equity trading at investment firm Shanshan Finance, referring to the 3,000 points - a key psychological level closely watched by many traders.
"But the state of stability could be temporary."
On Friday, the iVX index, which reflects expectations of future volatility in the SSE50 index, rose as high as 13.4. The "fear gauge" shot up to 12.35 on Thursday, the highest closing level in four months.
Also suggesting an increasingly divergent market outlook, trading in China's stock options almost doubled on Thursday to 1.57 million contracts, the highest on record.
Banking and property shares pulled back after the previous session's jump, but transportation stocks were firm.
In Hong Kong, the Hang Seng index was unchanged at 25,637.28 points, while the Hong Kong China Enterprises Index gained 0.2 percent, to 10,592.10.
Reporting by Samuel Shen and John Ruwitch; Editing by Jacqueline Wong