* HSI -1.1 pct, H-shares -1.4 pct, CSI300 -1.0 pct
* Banks down on mainland after weak data
* HK auto shares retreat after strong earnings amid regulatory concerns
By Natalie Thomas
BEIJING, April 15 (Reuters) - China shares fell on Tuesday as weak banking stocks weighed on sentiment after data showed the country's money supply grew at its slowest pace in more than a decade and loan growth slowed.
Hong Kong stocks also fell, dragged lower by auto shares, which shed some of the gains seen over the past few days after positive earnings data. The sector is also being affected by uncertainties over regulations that may curb demand.
By the midday break, the CSI300 index of the largest Shanghai and Shenzhen A-share listings was down 1.0 percent, while the Shanghai Composite Index eased 0.8 percent to 2,114.6 points.
The Hang Seng Index was down 1.1 percent at 22,788.68 points. The China Enterprises Index of the top Chinese listings in Hong Kong dropped 1.4 percent.
Banking shares led the decline on the mainland, with the CSI300 banking sub-index falling 1.6 percent after China's money supply grew at its weakest pace in more than a decade in March. Analysts said a depreciation in the yuan appeared to have slowed capital inflows and the build-up of foreign exchange reserves.
Total outstanding loans in March also slowed to an eight-year low of 13.9 percent, Thomson Reuters data showed, an indication that the de-leveraging process in financial institutions continues, analysts said.
Hua Xia Bank Co Ltd was down 2.3 percent, while Industrial Bank Co Ltd lost 2.2 percent and China Citic Bank Corp Ltd shed 1.8 percent.
The encroachment of online financial management products and their impact on interbank lending rates is also worrying investors, said Tian Weidong, head of research in Kaiyuan Securities in the city of Xi'an.
"There are several new products with much higher interest rates on savings and people predict that banking results will go down in the future because of this."
In Hong Kong, auto stocks were a major drag on index performance after investors decided to lock in gains following positive earnings results over the last month, as future growth prospects for the industry remain unclear.
Guangzhou Automobile Group Co Ltd shares lost 3.4 percent, Great Wall Motor Co Ltd was down 4.2 percent, and Dongfeng Motor Group Co Ltd lost 1.9 percent.
"Overall, the fundamentals are not that stable, so I think if there is some retrenchment it's normal," said Linus Yip, a strategist at First Shanghai Securities in Hong Kong.
Investors are chiefly concerned that vehicle purchasing limits, currently in place in four cities, may be further rolled out across the country as part of government efforts to tackle pollution.
One bright spot in the mostly lacklustre market was Universal Scientific Industrial Shanghai Ltd, whose shares hit their daily trading limit after the electrical goods manufacturer announced plans to raise up to 2.06 billion yuan ($331.24 million) via a private placement of shares.
$1 = 6.2191 Chinese Yuan Editing by Jacqueline Wong