* HSI +0.5 pct, H-shares +0.4 pct, CSI300 flat
* Midday volumes in HK and Shanghai among year's weakest
* Li & Fung lifted by UBS upgrade, chairman's comments
* ANTA Sports jumps after better-than-expected Q1 SSSG
By Clement Tan
HONG KONG, May 15 (Reuters) - Hong Kong stocks rebounded from a one-week low on Wednesday with a 7 percent surge in shares of top supply chain manager Li & Fung after its chairman said he expected earnings to rise to 2011 levels while UBS upgraded the stock.
Mainland China markets were broadly flat, with midday volumes in both on and offshore Chinese markets among the weakest this year as Premier Li Keqiang warned that the country has limited scope for policy stimulus to boost the economy.
At midday, the Hang Seng Index was up 0.5 percent at 23,046.3 after closing on Tuesday at its lowest since May 6. The China Enterprises Index of the top Chinese listings rose 0.4 percent.
The CSI300 of the leading Shanghai and Shenzhen A-share listings was flat, while the Shanghai Composite Index slipped 0.1 percent in the weakest midday bourse volumes in a month.
"I think people are still quite complacent, the official tolerance for a China growth slowdown is substantially higher than what people think," said Hong Hao, chief strategist at Bank of Communication International Securities.
Growth-sensitive counters such as China Coal were among the bigger underperformers, diving 5.2 percent in Hong Kong, while slipping 0.9 percent in Shanghai.
Gains so far on Wednesday lifted Li & Fung to its highest since March after its chairman, William Fung, said 2013 earnings would rebound to 2011 level as most performance targets have been met, according to Hong Kong media.
Shares of the supply chain manager for Walmart Stores Inc and Target Corp were also helped by an upgrade by UBS analysts from "sell" to "neutral," assuming a lower settlement of payables for the company.
There were also strong gains for ANTA Sports, which soared 6.4 percent as investors cheered its flat same-store sales growth in the first quarter after the company had warned of negative figures for the first two months of the year while reporting its 2012 annual results.
Sun-Art Retail climbed 2 percent after China's largest hypermarket chain by market capitalisation said first-quarter net profit rose 16 percent from a year earlier as it continued to expand into lower-tier Chinese cities.
SJM Holdings climbed 2.8 percent to a record high and could extend gains after the Macau casino operator said at midday the Macau government has given it the go-ahead for a project on the Cotai strip in the gambling hub.