* CSI300 +0.3 pct; SSEC +0.2 pct; HSI +0.3 pct
* B shares stabilise after regulator clarifies new system
* China c.bank pledges to keep reasonable credit growth
SHANGHAI, Dec 29 (Reuters) - China stocks stabilised on Tuesday after the previous session's more than 2 percent drop, as the central bank vowed to maintain reasonable credit growth and keep the yuan stable.
Hong Kong shares also edged up, but trading remained thin.
The blue-chip CSI300 index rose 0.3 percent, to 3,737.68 points by the lunch break, while the Shanghai Composite Index gained 0.2 percent, to 3,539.87 points.
Investor sentiment calmed after Shanghai-traded, dollar-denominated B shares - whose nearly 8 percent tumble on Monday dragged the overall market lower - rebounded.
In an apparent move to sooth investors, China's foreign exchange regulator said on Tuesday that a new business supervision system to be launched next month won't change the way Chinese individuals use currencies and has nothing to do with capital market fluctuations.
The new system was cited by some analysts as the reason behind the B share slump.
Investors also drew some solace from a People's Bank of China statement saying it would "flexibly" use various policy tools to maintain appropriate liquidity.
Wei Fengchun, strategist at Bosera Asset Management Co, predicted that the government would unveil more policies to support the economy in 2016, creating room for upward revision in China's growth forecast.
However, the stock market will likely be volatile, because "it's hard to foresee when policies will be rolled out and when the economy will stabilise," he wrote, suggesting investors be neither too pessimistic, nor optimistic.
And to ease investor concerns that the quality of listed companies would sharply deteriorate as China adopts a U.S.-style registration-based IPO system as early as next March, 22 government agencies agreed on Monday to jointly punish listed firms identified by the securities regulator to have broken the law.
Performance was mixed among sectors, with banking and resource shares rising, but transportation and infrastructure stocks flagging.
Shares of Hua Xia Bank rose 2.9 percent after Deutsche Bank agreed to sell its 20 percent stake in the Chinese lender to insurer PICC Property and Casualty Co for up to 25.7 billion yuan ($4 billion), ending a major source of uncertainty.
In Hong Kong, the Hang Seng index added 0.3 percent, to 21,989.21 points, while the Hong Kong China Enterprises Index gained 0.1 percent, to 9,794.95.
All main sectors rose, with the exception of energy shares .
Reporting by Samuel Shen and Nathaniel Taplin; Editing by Jacqueline Wong