Hong Kong stocks ended in the red on Wednesday as the Hang Seng Index finished down 1.22 percent lower at 26,163.
But up north, mainland stocks edged up to a three-month high led by artificial intelligence and chip sectors.
The blue-chip CSI300 index added 0.7 percent at market close after hitting its strongest level since January 14.
The Shanghai Composite index closed 0.5 percent higher at 4,106.26, its third straight session of gains.
Tech sectors led the gains, with the AI industry index adding 3.3 percent and chip sector index gaining 2.9 percent.
The CSI 5G Communications Index climbed 5.1 percent.
ChiNext Index, a Nasdaq-style second board for startups, added 1.7 percent to the highest level since 2015.
US President Donald Trump said he would indefinitely extend the ceasefire with Iran to allow for further peace talks.
Although it was not clear on Wednesday whether Iran or Israel would agree, investors largely took heart from the development.
"Middle East geopolitical risks are gradually easing, and the market is becoming increasingly desensitised to geopolitical conflicts," analysts at Nanhua Futures wrote in a note.
"Markets are now building an upward momentum, with earnings improvements likely becoming the core driver for the next phase.
"The improvement in liquidity conditions and rising investor risk appetite are working in tandem, driving stock indices higher," they added. (Reuters)
Edited by Tony Sabine
