Tekelec (TKLC) disclosed in an 8-K filing with the SEC this afternoon that it is having trouble selling some of its holdings in auction rate securities.

Tekelec says that since December 31, the company has reduced its holdings in auction-rate securities from $199.8 million to $127.4 million. The company says all of the securities are AAA rated by one or more rating agencies and collateralized by student loans, with 92% of such collateral guaranteed under the Federal Family Education Loan Program. However, the company said it has “recently experienced several failed auctions for the portion of its auction rare securities that has gone to auction, resulting in the company’s inability to sell these securities.”

The company said it may reclassify some (or all) of its auction-rate holdings from current assets to long-term assets in the first quarter, which could reduce working capital to about $175 million. Tekelec says that should still be “adequate” to fund its current business plan even if the company “loses access for extended periods of time to the entire amount invested in auction rate securities.”

Tekelec says it believes the current carrying value of the holdings approximate fair value.

This is not the only tech company struggling with cash investments that now face liquidity issues; ADC Telecom (ADCT) recently took a charge for the impaired value of auction-rate securities.

In after hours trading, Tekelec is down 7 cents at $12.09.