Oct. 24 (Bloomberg) -- The Polish zloty, Hungarian forint and South African rand headed for their biggest weekly declines as the global economic slump fuels concern of a worsening credit crisis in emerging markets.

The zloty fell 3 percent against the dollar today, taking its weekly decline to more than 16 percent, the steepest since Bloomberg began tracking the data in 1993. The forint extended its weekly loss to a record 14 percent while the rand fell almost 17 percent in its biggest five-day slump since 1975.

Investors are selling emerging-market stocks, bonds and currencies as the rout that began with the collapse of U.S. subprime mortgages last year pushes the world toward a recession and lowers the price of commodities that sustain developing economies. South Korea's central bank said fourth-quarter economic growth was the slowest in four years, sending the Kospi stock index 11.7 percent lower today, capping its worst week since 1997, and pushing the won near a 10-year low.

``We're seeing funds fly out of Hungary, Poland and other eastern European countries,'' said Silvia Marengo, who manages about $130 million of emerging-market bonds at Clariden Leu in London. ``The countries with the biggest falls are the economies that were most connected to developed nations.''

Foreign-currency loans make up 62 percent of all household debt in Hungary, up from 33 percent three years ago, and the nation has a larger budget deficit than anywhere else in eastern Europe. Hungary's economy grew 2 percent in the second quarter, compared with 5.8 percent in Poland.

Forint Fall

The forint has plunged almost 30 percent this year against the dollar. The Budapest stock exchange index, which has lost more than half its value this year, fell 3.4 percent today to the lowest since 2003.

Polish central bank Governor Slawomir Skrzypek said today he doesn't envisage any ``intervention on the foreign exchange market'' after the zloty's more than 20 percent slide against the dollar this year. The nation's benchmark WIG20 stock index dropped 5.9 percent today.

``The financial crisis is changing its nature at the moment, away from fear of systemic risk attached to money and credit markets and toward emerging markets and the economic consequences of the financial crisis,'' Lars Christensen, an emerging markets analyst at Danske Bank A/S in Copenhagen said in a research note.

The plunge in commodity prices, which this week slid to the lowest level in four years, has contributed to a more than 70 percent drop in the rand this year. Commodities make up more than half of South Africa's earnings abroad, according to data from the Department of Minerals and Energy.

South Africa's key stock index fell to the lowest since June 2006, dropping 4.3 percent, as investors sold commodity stocks led by BHP Billiton Ltd., the world's largest mining company.

MSCI Declines

Emerging-market stocks fell for a fourth day, with the MSCI Emerging Markets Index declining 6.2 percent to a five-year low of 482.24 at 11:25 a.m. in London. The Korean Kospi stock index was 11.7 percent lower today, capping its worst week since 1997, and pushing the won near a 10-year low.

India's Sensex benchmark headed for the biggest daily slump since 2004 after the central bank said it will continue fighting inflation, reducing the likelihood of easier lending to bolster growth. The Czech PX index slid 8.6 percent, the most in a week.

Russia's Micex Index tumbled 7.5 percent before trading was halted for an hour. The yield on Russia's 30-year, 7.5 percent dollar notes increased to more than 12 percent for the first time since 2002.

The extra yield investors demand to own developing nations' bonds instead of U.S. Treasuries rose 11 basis points to 8.68 percentage points, a six-year high, according to JPMorgan Chase & Co.'s EMBI+ Index.

To contact the reporter on this story: Laura Cochrane in London at lcochrane3@bloomberg.net

Last Updated: October 24, 2008 06:36 EDT