Zenith Electronics Corp, Glenview Illinois, says its has secured $60m in unsecured and uncommitted credit facilities, in the form of two $30m lines of credit with the Bank of America and First Chicago NBD. the credit lines are guaranteed by LG Electronics Inc, the largest shareholder in Zenith. The company is also calling its 8.5% senior subordinated convertible debentures due November 2000 with a call date of December 5 and a call price of 104. In addition Zenith will call its 8.5% debentures due January 2001 in January 1998. The current outstanding amounts are $23.75m and $550,000 for the notes due 2000 and 2001, respectively.