NEW YORK (TheStreet) -- Magnachip Semiconductor (MX_) is tumbling in extended trading on the announcement its chief financial officer Margaret Sakai had resigned and that its accounting review would be delayed.<br /><br />After the bell, shares are down 7% to $13.50.<br /><br />The semiconductor manufacturer said Sakai had resigned as CFO and executive vice president, effective immediately, and that senior vice president and chief accounting officer Jonathan Kim would stand as interim CFO until a replacement had been found.<br /><br />The board is currently commencing its search for a permanent replacement.<br /><br />Magnachip also reaffirmed its March 11 announcement that it has commenced an internal review of its accounting practices and that the process remains ongoing.<br /><br />"While substantial progress has been made, it is expected that this review and work with regard to the previously announced restatement will take several more months, and as a result the Company will be postponing its annual investor conference to a date to be announced after the filing of its Annual Report on Form 10-K," the company said in a statement.