Close to a thousand members of South Africa's Solidarity union held a demonstration on Wednesday over pay at cash-strapped State-owned weapons manufacturer Denel.

Denel, which produces military equipment for South Africa's army and foreign forces, has held talks with unions over voluntary severance packages, reduced working hours and salary cuts for some staff as it struggles to emerge from a financial crisis.

The company did not pay managers and specialists their full salaries in September.

The workers held the protest after Denel said it will be able to pay salaries in October but salaries for November and other allowances were not guaranteed.

"We're bringing attention to the board that they're sitting with a huge number of unhappy and insecure employees not knowing if they'll have an income next month," said Solidarity's Deputy General Secretary Johan Botha.

"The Denel board needs to implement a turnaround strategy as soon as possible ... to pull this issue out of the fire."

The strikers handed over a memorandum and a petition of their grievances to Denel CEO Michael Kgobe, he said.

Denel spokesperson Pam Malinda said there was no dispute between the company's management and labour.

"There is no protected strike or lockout taking place, which may raise legal questions about the rationale and applicability of a picket," she said in a statement.

A protected strike prohibits employers from dismissing employees for participating in the industrial action and also prevents companies from taking civil legal action against the strike.

"The Board and management will continue with its efforts to turn the company around, strengthen corporate governance and stabilise Denel's financial position," Malinda added.

In April President Cyril Ramaphosa oversaw the appointment of a new board at Denel as part of a wider plan to improve the governance and finances of state firms.

Saudi Arabia has approached South Africa about taking a stake Denel, the African country's foreign affairs minister Lindiwe Sisulu confirmed last week.