Financials and commodities lead Europe shares lower

* FTSEurofirst 300 falls 3.4 percent

* Financials, commodities lead index to 5-1/2 year low

* Ahold, RBS lead risers

By Brian Gorman

LONDON, Nov 20 (Reuters) - European stocks fell to the their lowest level since March 2003 early on Thursday, adding to the previous session's selloff, as banks and commodities continued their slide on worries of a deep global slowdown.

At 1006 GMT, the FTSEurofirst 300 .FTEU3 index of top European shares was down 3.4 percent at 784.21 points, having fallen as low as 782.67.

The benchmark index has fallen more than 48 percent this year.

"There's no volume. No one wants to buy. People will take opportunities to sell," said Justin Urquhart Stewart, director at Seven Investment Management.

"No one wants to float a boat -- they will wait for the tide to turn. What will make it turn? We have to get the bad news completely out the way. That may come when there are more realistic valuations of properties in the United States."

European banks remained under pressure after Citigroup Inc (C.N) faced a crisis of confidence on Wednesday as investors questioned the survival prospects of the U.S. banking giant, and its shares tumbled 23 percent to a 13-year low.

"Having seen Lehmans and Merrill Lynch fall by the wayside this year, the sight of another major such as Citigroup struggling will prove a bitter pill to swallow," said Chris Hossain, senior sales manager at ODL Securities.

Dexia (DEXI.BR), Fortis (FOR.BR), Barclays (BARC.L), Credit Suisse (CSGN.VX), Banco Santander (SAN.MC) and UBS (UBSN.VX) fell between 5.9 and 9 percent.

But BNP Paribas (BNPP.PA) was outperforming, down 0.3 percent, after announcing late on Wednesday that it is not considering any capital increase other than that already scheduled to finance the acquisition of Fortis Bank, which will be subscribed by the Belgian and Luxembourg states

Insurers continued to fall, with their equities portfolios hurt by the slide in the stockmarket.

Axa (AXAF.PA), Aviva (AV.L), Prudential (PRU.L), Swiss Life (SLHN.VX) and Zurich Financial (ZURN.VX) fell between 5.1 and 8.9 percent.