The  JSE opened lower on Tuesday as markets remain cautious ahead of the US-China trade talks at the Group of 20 (G20) summit later this week. 

Investors are awaiting the outcome of the trade talks between US President Donald Trump and Chinese president Xi Jinping, with some analysts sceptical about a trade deal being reached at the summit in Osaka, Japan.

“Equity markets have already priced in a slim chance for a sudden resolution of trade tension between the US and China at this week’s Group of 20 meeting. Both Chinese and US officials have given few signs of compromise to find common ground to move forward. As such, a no-deal will likely see limited negative kneejerk reaction from equity traders, but any positive step could revive the bulls,” senior market analyst at London Capital Group Ipek Ozkardeskaya said 

On Monday, the US imposed further sanctions on Iran after the latter shot down a US drone, as tension escalates between the two countries. 

In Asia, the Shanghai composite had fallen 0.87% and Hong Kong's Hang Seng 1.27%, while Japan's Nikkei 225 was up 0.13%.

By 10.am, the JSE all share had fallen 0.24% to 58,614.80 points and the top 40 was 0.24% lower. Gold miners had climbed 3.58% and platinum miners 3.14%.

Omnia jumped 6.29% to R36.50 after the fertiliser and chemicals company said its revenue rose 7% to R18.6bn for the year ended March. 

African Rainbow Capital was up 0.82% to R4.90. On Tuesday, the company announced changes in the leadership of its subsidiary, TymeBank, including the resignation of its CEO, Sandile Shabalala. 

Digital technology company Etion said its revenue rose 4% to R595.9m for the year to end-March.