* Mark Liu to become chairman, Wei to become sole CEO
* Leadership change comes amid diversification push
* Samsung seeking to become fearsome rival to TSMC
* TSMC now has market value of about $185 bln (Adds analyst's comments)
TAIPEI, Oct 2 (Reuters) - Taiwan Semiconductor Manufacturing Co (TSMC) founder and chairman Morris Chang will retire in June, after having built the Apple Inc supplier into the world's biggest foundry chipmaker with a market value of about $185 billion.
Chang, who is 86 and is known as the father of Taiwan's chip industry, will be succeeded as chairman by Mark Liu who has been co-CEO along with C.C. Wei since 2013, TSMC announced on Monday. Wei will become the sole CEO.
The change in leadership comes at a critical time as TSMC, which has thrived on booming demand for chips used in smartphones, now seeks to diversify its customer base and move into emerging industries such as artificial intelligence and autonomous driving.
It must also deal with a growing threat from Samsung Electronics, the world's top memory chipmaker, which plans to triple the market share of its contract chip manufacturing business within the next five years by aggressively adding clients.
The succession plan has been in the works for years. Liu and Wei have held complementary posts since 2012 when they were chief operating officers before assuming co-CEO roles in 2013. Previously, they were senior vice presidents - Wei for business development and Liu for operations.
Liu studied electrical engineering and computer science at the University of California, Berkeley. Wei studied electrical engineering in Yale University. Both Liu and Wei have doctorates.
Chang, citing personal and family reasons, said that upon his retirement, he would not sit on the board of directors or participate in management activities.
He founded TSMC in 1987 with paid-in capital of T$1.4 billion ($45 million) and pioneered contract chip manufacturing for chip design firms which don't have their own factories. He has been its chairman since then.
Chang spent 25 years at Texas Instruments and holds a doctorate from Stanford. Born in China, he went to Taiwan in 1985 after being recruited by the government to head a body promoting industrial and technological development.
TSMC has since grown to command 56 percent of the $47 billion market while revenue has climbed to around $30 billion in 2016.
The planned leadership succession will not change the company in a fundamental way, analysts said.
"I think Liu and Wei will continue TSMC's current model for some years," said Mark Li, an analyst at Sanford C. Bernstein. "I do see the increasing cost of newer generation technologies as an issue but for now TSMC will still maintain the cadence of R&D development."
But if something new comes up, such as uses of new technology that increases TSMC's cost, they'll need to change their plan accordingly, Li said.
Prior to the announcement, shares of TSMC closed up 1.85 percent. They have risen 22 percent so far this year, making it the most valuable firm in the Thomson Reuters Global Semiconductor Index, ahead of stalwarts such as Intel Corp and NVIDIA Corp. (Reporting by Jess Macy Yu; Additional reporting by Miyoung Kim; Editing by Edwina Gibbs and Muralikumar Anantharaman)