Terry Gou, the founder of Foxconn, has decided to quit the Kuomintang (KMT), effective immediately, his spokesperson told reporters on Thursday, a move that came after months of speculation that the billionaire-turned politician would run as an independent in 2020 Taiwan leadership election.

In July, Gou lost the KMT's primary race to Kaohsiung mayor Han Kuo-yu.

Gou will make a decision on whether to run as an independent by September 17, the deadline for next year's election registration, local media reported, quoting Gou's office. 

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Thursday's announcement came shortly after the KMT published a half-page advertisement in several major local newspapers, appealing for unity and asking Gou to cooperate in January's election with Han.

The advertisement, signed by 31 senior KMT figures, called Gou to work with Han to rescue cross-Strait relations.

Spokeswoman Tsai Chin-yu said Gou made the decision because the KMT prioritizes partisan gains ahead of Taiwan's interests, which runs counter to his original desire to join the party.

The spokeswoman, citing Gou, called KMT "an out-of-date party."