HONG KONG, March 11 (Reuters) - Hong Kong shares surrendered midday gains to close flat on Monday, weighed down by a lacklustre mainland market after patchy economic data over the weekend spawned doubts about the earnings outlook for Chinese firms.
The Hang Seng Index ended flat at 23,090.8, lingering around Friday's closing level, which was its highest since Feb. 20. The China Enterprises Index of the top Chinese listings in Hong Kong shed 0.4 percent on Monday.
The CSI300 index of the leading Shanghai and Shenzhen A-share listings closed down 0.6 percent at 2,592.4. The Shanghai Composite Index slipped 0.4 percent.
* Chinese oil giant CNOOC fell 1.1 percent on weak oil prices after official data over the weekend showed China's consumer prices rose 3.2 percent in February from a year ago, their biggest increase in 10 months. Industrial production growth in the first two months of 2013 was the lowest since October 2012 - the starting point of China's nascent economic recovery.
* Yurun Food, one of a series of Hong Kong-listed Chinese companies that over the weekend warned of declining profitability, tumbled 7 percent to close at its lowest since Dec. 12. Lead acid battery maker Coslight plunged more than 23 percent.