Taiwan's Fair Trade Commission (FTC) has decided to terminate its review of an application submitted by Advanced Semiconductor Engineering (ASE) to acquire additional Siliconware Precision Industries (SPIL) shares which would boost ASE's ownership in SPIL to almost 50%.

Considering ASE's tender offer for another 24.71% stake in SPIL has already expired and will not be extended, the FTC decided to terminate the review of the deal, according to the authority.

SPIL has responded saying the company is "extremely pleased" with the decision made by the FTC, while ASE has argued the decision is "completely without legal basis and violates the FTC's own administrative precedents."

ASE, after securing a 25% stake in SPIL through an unsolicited tender offer in October 2015, launched another tender offer in December aiming to obtain a controlling stake in the fellow packaging and testing house. The bid, however, failed to obtain regulatory approval before it expired on March 17.

The FTC could not make a final decision before March 17 although the deadline set for reviewing the case had yet to expire.

ASE, which had already extended the deadline of its tender offer for additional SPIL shares, is not allowed to extend the offer period for a second time according to Taiwan's law. The law will also forbid ASE from making another tender offer for SPIL shares within one year after its failure to meet the regulations.