South Korean chipmaker SK Hynix Inc. is asking for up to 33.4 percent of voting rights in Toshiba Corp.'s semiconductor unit as they continue talks on the sale of the business, according to sources.

SK Hynix has joined a consortium chosen by Toshiba as a preferred bidder for Toshiba Memory Corp. SK Hynix would provide loans to a U.S. fund participating in the joint bid, as Toshiba is concerned it may take longer to clear antitrust reviews if a chipmaker takes a stake in the unit.

Western Digital Corp., Toshiba's joint chip production partner, is opposed to any sale to a third party without its consent.