The Tokyo bourse has delisted the stock of Elpida Memory, which filed for bankruptcy protection on February 27.

Elpida started trading on the Tokyo Stock Exchange in November 2004.

In the meantime, Elpida also stopped trading its shares in Taiwan on March 28. The shares, issued in the form of Taiwan depositary receipts (TDRs), were launched in February 2011.

Elpida's bankruptcy filing has put pressure on its Taiwan-based production subsidiary Rexchip Electronics, and supply-chain partners including Powerchip Technology and Powertech Technology (PTI).

Elpida reported its fifth straight quarterly loss in the three months ended December 31, 2011.

In other news, Taiwan-based DRAM chipmaker ProMOS Technology was delisted from Taiwan's over-the-counter (OTC) stock market on March 26. Trading of the company's shares had been suspended since September 2011 on failure to submit its financial results before a required deadline.

ProMOS swung to net losses in the second quarter of 2007, and has remained unprofitable since.