The JSE has suspended South African State-owned defence company Denel's bonds after it failed to submit financial results within the required timeframe.

The suspension means investors cannot trade Denel's bonds on the JSE's secondary market nor can Denel sell more debt on the primary market.

It marks the latest chapter in the decline of Denel, which produces weapons and ammunition for South Africa's armed forces and overseas clients including in the Middle East.

The firm was once the cornerstone of the local defence industry but has suffered severe liquidity constraints that have hurt its ability to deliver on orders. It was allocated another government bailout in November to help it repay debt.

According to the JSE's debt listing requirements, a state company has to submit its annual financial statements within seven months of its financial year-end.

Denel is yet to publish its results for the year ended March 2021. Its results for the year ended March 2020 were also delayed and showed an almost 2 billion rand ($130 million) loss.

"The JSE has made the decision to suspend the issuer's debt securities with immediate effect. This announcement has been placed by the JSE in the interest of debt security holders," the exchange said in a notice on Wednesday.

Denel declined to comment.

Refinitiv Eikon data show Denel has 140 million rand of outstanding bonds.

In prior years South African state-owned asset manager the Public Investment Corporation (PIC) held a large amount of Denel's listed debt. Reuters submitted questions to the PIC, which said it was working on a response.

In a separate JSE notice on Wednesday, investors were told that Denel had experienced a delay in processing an interest payment and capital redemption.

"Denel and its shareholder are currently finalising the necessary approvals for the payments which will be made as soon as the approvals are in place," it read.