With no sectors in the blue today amid heavy falls in equity prices, banks and miners are among the worst performers.Banks are under the cosh on concerns over Dubai's debt situation. The government owned Dubai World, which has debts of $59bn, has asked creditors if it can delay debt repayments due next month until May of next year. HSBC, Royal Bank of Scotland, Barclays, Lloyds Banking and Standard Chartered all feature prominently among the biggest fallers on Footsie.The country stunned financial markets late yesterday when it announced that Dubai World and its subsidiary Nakheel were seeking a debt standstill ahead of a restructuring.In a statement, the Dubai government said: "Dubai World intends to ask all providers of financing to Dubai World and Nakheel to 'standstill' and extend maturities until at least 30 May 2010."With metals prices falling, mining stocks are on the back foot.Among the fallers is Antofagasta. Profits fell by nearly half at the South America-focused miner as tumbling metals prices hit sales.Earnings before interest, tax depreciation and amortization (EBITDA) fell to $1.13bn from $2.22bn the same period a year ago as sales fell by 39% to $2.02bn.The fall in Antofagasta's sales mirrored a drop in average copper prices to $2.50 a pound from $3.49. Prices for silvery metal Molybdenum, fell to $11.9 a pound from $33.2.Bottom performing sectors so far todayBanks 4,866.42 -4.82%Life Insurance 3,851.05 -4.43%Forestry & Paper 3,420.98 -3.79%Mining 20,293.45 -3.30%Construction & Materials 3,203.74 -2.89%