* CSI300 +0.1 pct; SSEC +0.1 pct; HSI +0.6 pct
* Investors divided on China market direction
* HSBC rises after CEO says weighing share buyback
SHANGHAI, April 19 (Reuters) - China stocks ended Tuesday morning roughly flat, as investors were split on whether the country's economic recovery, and thus a market rebound, is sustainable.
But Hong Kong shares joined a regional rally, aided by a rebound in crude prices that was sparked by an oil workers' strike in Kuwait, a major oil producing country.
Both the blue-chip CSI300 index and the Shanghai Composite Index gained 0.1 percent by lunch time, to 3,035.09 points and 3,230.12 points, respectively.
In Hong Kong, the Hang Seng index added 0.6 percent, and the Hong Kong China Enterprises Index gained 0.7 percent.
China stocks have bounced around 15 percent off Feb. 29 lows, lifted by upbeat first-quarter economic data including for industrial output, exports and retail sales.
But China's policy advisers caution that it is too early to call an end to a cycle of easing that began in 2014, while analysts call for deeper, broader economic reforms.
"Signs of recovery came mostly from the old engines of the economy, such as infrastructure, real estate and cement, which means structural reforms have progressed more slowly than expected," said Song Yiwei, strategist at Bohai Securities in Tianjin.
"More aggressive reforms are needed to make the recovery sustainable," he said.
On Tuesday, market sentiment was aided by central bank's fresh measures to inject liquidity into the banking system, via both medium- and short-term liquidity tools.
Gains in transportation and resource shares offset losses in telecommunication and energy stocks.
In Hong Kong, energy shares rebounded on higher oil prices, while the financial sector rose sharply, led by index heavyweight HSBC Holdings, which gained 2.7 percent.
HSBC Chief Executive Stuart Gulliver told shareholders in Hong Kong on Monday that the bank is studying the possibility of buying back some of its shares.
Reporting by Samuel Shen and Nathaniel Taplin; Editing by Richard Borsuk