NEW YORK - The House's rejection of the financial bailout plan sent the credit markets into further disarray Monday, with investors swarming again for the safety of Treasury bills.

If the credit markets stay tight, it could spell trouble for companies trying to raise cash by selling short-term debt in the coming weeks. If those companies' efforts are thwarted, the economy could grow even weaker.

After the Dow Jones industrial average plunged nearly 780 points on Monday -- the biggest daily point drop ever -- the yield on the three-month Treasury bill sank to 0.14 percent from 0.87 percent late Friday. Low T-bill yields show that investors are prepared to get virtually no return on an investment as long as it is secure.

Earlier Monday, the LIBOR, or London Interbank Offered Rate, for three-month dollar loans had risen to 3.88 from 3.76 percent on Friday, suggesting that banks have grown increasingly unwilling to lend to each other. LIBOR for three-month euro loans, meanwhile, soared to 5.22 percent, the highest ever.

Other lending rates increased, too, from already lofty levels -- including those on short-term company debt known as commercial paper, and those on overnight loans in the repo markets, where banks and other institutions do temporary borrowing.

The mortgage crisis is also ripping through Europe. The British government is nationalizing the troubled mortgage lender Bradford & Bingley, while Belgium, the Netherlands and Luxembourg agreed to buy a 49 percent stake in Fortis NV for $16.4 billion. Germany organized a credit lifeline for commercial real estate lender Hypo Real Estate Holding AG.