Amkor rises on margin expansion, growing AI-driven computing revenue

** Shares of semiconductor packaging and testing company Amkor AMKR.O rise 2.8% to $37.9 premarket

** Co posts Q3 gross margin of 18.3%, up from 14.3% a year ago

** Reports computing and automotive and industrial sectors revenue of 26% and 22%, up from 19% and 16% a year ago, respectively

** Reports Q3 sales of $1.99 bln, slightly up from $1.98 bln a year ago

* On Oct 21, co and Nvidia advance $1.3 bln strategic partnership for AI infrastructure

** Six of 13 brokerages rate the stock "buy" or higher, six "hold" and one "sell"; median PT is $64.26

** As of last close, stock down 6.8% YTD