NEW YORK (Bloomberg) ? Bonds of Sea Containers Ltd., the operator of high-speed rail lines in the UK, tumbled ahead of a $115 million debt maturity the company has said it might not be able to make.

The company?s $115 million of 10.75 percent notes due on October 15 fell 11.5 cents today to 70.5 cents on the dollar to yield about 70 percent, according to Trace, the bond-price reporting system of the NASD. Bermuda-based Sea Containers in August said it may not repay the securities.

?Most holders are now assuming a bankruptcy,? John Parker, a debt analyst at Jefferies & Co. said in an interview from his Short Hills, New Jersey, office. Sea Containers? bonds are falling as investors reduce their recovery expectations, he said.

Sea Containers? $150 million of 7.875 percent notes due in 2008 fell 7.5 cents to 76 cents on the dollar to yield 31 percent, Trace data show.

The debt is rated Caa3 by Moody?s Investors Service and CC by Standard & Poor?s, the third and second-lowest ratings. ?Sea Containers has very constrained liquidity,? S&P analysts said in an August report. ?Available cash was only $80 million at July 31, 2006, with no available borrowing capacity.?

In July, GNER, the UK train operator owned by Sea Containers, lost a legal bid to block two competitors from running passenger services on parts of its main route.

Shares of the company fell 26 cents to 72 cents. They traded as high as $21.44 as recently as March 2005.