Taiwan Semiconductor Manufacturing Company (TSMC) has given its cautious business and overall chip industry outlook this year, when the pure-play foundry is likely to remain the only supplier of Apple's A-series chips.

TSMC will be the exclusive supplier of Apple's custom-designed chips dubbed the A13 that will power the 2019 series of iPhones. The foundry is scheduled to enter volume production of the chips built using 7nm process technology including an enhanced version with EUV in the second quarter of 2019, according to sources familiar with the matter.

TSMC CEO CC Wei said at the company's investors meeting in January that sales generated from 7nm process technology are forecast to account for more than 25% of company revenues this year. Wei added that the foundry's 7nm chip client portfolio is "growing stronger" as more chip designs for applications such as HPC and automotive demand the process.

Despite the optimism about its 7nm chip sales, TSMC expressed caution about the foundry's overall operations citing factors on a macro level. The foundry expects 2019 to be "a slow year" for its business and also the global chip sector. It forecasts that the foundry segment will register only flat growth.