March 2 (Bloomberg) -- Spansion Inc., the U.S. maker of memory chips for mobile phones, filed for bankruptcy protection to restructure its debt after failing to make an interest payment on $266 million of bonds.

The company listed debt of $2.4 billion and assets of $3.8 billion as of the end of the third quarter of 2008 in Chapter 11 documents filed yesterday in U.S. Bankruptcy Court in Wilmington, Delaware.

Spansion announced plans to cut 35 percent of its workforce on Feb. 23, after missing a second payment deadline on the notes. The Sunnyvale, California-based company hasn’t made a profit since it was spun off by Advanced Micro Devices Inc. in 2005, and has been hurt by slackening demand for semiconductors.

Spansion continues to explore strategic opportunities while attempting to restructure debt and focusing on operations with profit-generating potential, the company said yesterday.

“Chapter 11 provides the most effective means for Spansion to preserve its business,” Chief Executive Officer John Kispert said in a statement. Four subsidiaries also sought protection.

The shares slumped 61 percent to 2 cents in Nasdaq Stock Market trading at 4 p.m. New York time. They have fallen 99 percent since reaching a 52-week high of $3.70 in May.

The 65 largest unsecured consolidated creditors are owed $951.1 million, court papers show.

Possible Fujitsu Impact

Spansion’s biggest creditors listed include U.S. Bank NA and Wilmington Trust, owed $457 million for notes and debentures due in 2016; Fidelity Management & Research Co., owed $69 million for notes and debentures due in 2016; Chipmos Technologies Ltd, owed $57.7 million; TEL U.S. Holdings, owed $49.4 million; and AIG Global Investment Group Inc., owed $33.8 million for notes and debentures due in 2016.

Fujitsu Ltd., Japan’s biggest computer-services provider, is investigating the possible impact of Spansion’s filing, Toshiyuki Fukuoka, a company spokesman, said by telephone. A unit of Tokyo-based Fujitsu, Spansion’s largest shareholder with a stake of about 11 percent, sells the U.S. chipmaker’s products in Japan, Fukuoka said.

Spansion’s Japanese subsidiary filed for bankruptcy protection last month. The company is the world’s largest producer of NOR flash, once the most common type of memory chip used in mobile phones before handset makers turned to cheaper NAND flash chips manufactured by Samsung Electronics Co. and Toshiba Corp. instead.

The case is Spansion Inc., 09-10690, U.S. Bankruptcy Court, District of Delaware (Wilmington).

To contact the reporters on this story: Jeran Wittenstein at jwittenstei1@bloomberg.net; Dawn McCarty in Wilimington, Delaware, at dmccarty@bloomberg.net

Last Updated: March 2, 2009 16:07 EST