(Adds blackout contingency plan) JOHANNESBURG, Nov 20 (Reuters) - The South African Broadcasting Corporation (SABC) delayed a plan to lay off 600 employees by a week on Friday after threats of a radio and TV blackout by some of its presenters and journalists. The public broadcaster is among the heavily indebted state-owned firms that South African President Cyril Ramaphosa has promised to wean off public funding. Its staff of around 3,000 permanent employees and 1,500 independent contractors is among SABC’s biggest expenses, although unions say the high salaries of middle management and executives are to blame. The SABC board said this week it needed at least 1 billion rand ($65 million) a year to keep going, and that its plan to cut costs by reducing headcount was not yet working. “The Board of the SABC would like to announce that it will suspend the S189 process for a period of 7 days,” SABC said in a statement, referring to the South African law which requires employers to consult employees before implementing job cuts. “This will allow all stakeholders to further engage and explore further options in an effort to ensure the financial sustainability of the SABC,” it added. SABC’s annual report shows it lost 511 million rand ($33 million) in its 2019/20 financial year, compared with a 482 million rand loss the year before, with revenue from advertising, sponsorship and licence fees showing sharp falls. The broadcaster announced the plan to cut jobs in June as part of a restructuring dating back to 2018. In a separate statement the SABC said it was aware of a plan for a blackout on its platforms and that “there are contingency plans in place that will kick in immediately should this self-induced crisis be precipitated.” “There will be consequence management against any employee who is involved in the planned ‘blackout’,” the SABC said. ($1 = 15.3964 rand) (Reporting by Mfuneko Toyana; Additional reporting by Nqobile Dludla; Editing by Mark Potter and Alexander Smith)