TAIPEI TSMC, the world's largest contract chipmaker, will decide this week whether to invest in chip designer Arm Holdings' blockbuster initial public offering (IPO), Chairman Mark Liu said on Wednesday.

Speaking on the sidelines of the SEMICON Taiwan summit, Liu said his company was still evaluating the matter and, when pressed on when a decision may come, he added "this week".

"Arm is an important element of our ecosystem, our technology and our customers' ecosystem. We want it to be successful, we want it to be healthy. That’s the bottom line," Liu said.

On Tuesday, SoftBank Group's Arm Holdings launched the roadshow for its IPO as the chip designer tries to convince investors it is worth as much as $52 billion in this year's biggest share sale.

Speaking about Taiwan Semiconductor Manufacturing Co Ltd's (TSMC) plant in Arizona, Liu said he has no conern over its ability to be successful, adding that in the last five months, the improvement had been "tremendous."

(Reporting by Ben Blanchard; Editing by Anne Marie Roantree and Stephen Coates)