Royal Bank of Scotland is leading the banking sector lower.Trading in the state-controlled bank briefly stopped trading and it went into 'auction' as the price tumbled below 30p, though it has since recovered a little.The auction process is used when a company's share price falls, or rises too quickly in a short space of time. It is used to smooth out these falls and rises and make trading more orderly.Rumours that a bank tax in some form could accompany tomorrow's pre-Budget statement have unsettled the shares all week as have reports over its exposure to Dubai, and talk that the board may resign if a bonus cap is forced on the bank. All have resurfaced today.The media sector is one of the few risers, even though DQE, the animation, gaming and entertainment group, which has won an exclusive deal with Australian Broadcasting Corporation for the broadcasting of 52 episodes of the animated series of 'The Jungle Book' and a 60 minute TV Feature, is lower.Advertising group WPP and FT publisher Pearson are among the stocks lifting the sector higher.Top performing sectors so far todayMedia 3,249.40 +0.27%Technology Hardware & Equipment 332.96 +0.19%Bottom performing sectors so far todayIndustrial Engineering 3,743.26 -3.50%Automobiles & Parts 2,515.76 -3.41%Banks 4,666.13 -3.09%Forestry & Paper 3,601.94 -3.07%Life Insurance 3,758.85 -2.90%