The JSE opened weaker on Tuesday as global growth fears drove US and Asian markets lower. The Dow Jones industrial average closed 1.1% lower on Monday and the S&P 500 was 1.42% off. The Tokyo Nikkei 225 was 5.4% lower. Chinese markets were closed.A combination of concerns surrounding global growth and an absence of decisive central bank action continues to create a trading environment that is challenging for risk assets‚ Momentum SP Reid said in an early morning note.It said the S&P 500 had traded down towards significant support areas‚ with more weakness likely.At 9.37am‚ the all share was 0.93% lower at 48‚968.10 points and the blue-chip top 40 was 0.96% lower. Banks lost 1.99% and financials were 1.46% down. Platinums were up 3.44% and the gold index gained 3.17%.Naspers was one of the early casualties of the day. It traded 2.97% lower at R1‚795 and is now down 16% for the year so far.Among the big miners Anglo American was 0.95% higher at R85.30.Kumba Iron Ore was 2.15% lower at R45.99. It earlier reported headline earnings per share (HEPS) for the year to December 31 2015 fell 66% to R11.82 compared with the year-earlier period.AngloGold Ashanti was 5.02% higher at R184 among gold stocks.Anglo American Platinum was 3.33% up at R310. The stock has recovered 66% year-to-date. Lonmin added 10.10% to R17.99.Banks found little support ahead of the reporting season next month. Barclays Africa was 3.14% lower at R138.84. Capitec lost 2.4% to R490.93.Retailers also had a weak opening‚ with Truworths retreating 2.98% to R93.03. Shoprite shed 1.01% to R142.65.Pharmaceutical group Aspen was 1.96% weaker at R244.50. - TMG Digital/BDlive..