UPDATE 1-South African Airways workers to strike from Friday -unions

(Adds comments from Numsa SecGen, details, background)

JOHANNESBURG, Nov 13 (Reuters) - Cabin crew and other workers at South African Airways (SAA) will go on strike on Friday over the struggling state airline's plan to cut more than 900 jobs, unions said on Wednesday.

SAA has not made an annual profit since 2011 and is grappling with a funding gap of 21.7 billion rand on top of an aging fleet, is without a permanent chief executive, and has yet to file financial results for 2017/18 and 2019/20.

It has relied on government bailout to stay afloat, and on Tuesday confirmed it wanted to cut 944 of its staff to ease its financial pain and pay creditors, a move unions say is aimed at avoiding a granting workers an 8% wage increase.

"We are left with no choice but to resort to this drastic action by withdrawing our labor and going on strike," Zazi Nsibanyoni-Anyiam, president of the South African Cabin Crew Association, told a joint press briefing with the National Union of Metal Workers of South Africa (NUMSA).

The strike would continue indefinitely, said the unions which represent about 3,000 workers including check-in, ticket sales, head office, technical staff and ground staff.

"We want all workers to participate in the strike. We will ground the airline come Friday. The strike will be an indefinite strike until these people come to the table," NUMSA general secretary Irvin Jim at the briefing.

In October SAA and other carriers grounded aircraft and canceled domestic flights after the aviation regulator noted problems at SAA's maintenance unit, adding to worries about its viability as a business. (Reporting by Naledi Mashishi Writing by Mfuneko Toyana; editing by Susan Fenton and David Evans)