Key Points:

Shares of Casio Computer plunged the most in 32 years after the company missed its profit target and said it would expand in the crowded mobile-phone business.

The stock tumbled 16 per cent to 2035, wiping out about US$907 million ($1.24 billion) in Casio's market value.

Casio's plan to expand its phone unit globally comes after Benq Corp's failure to turn around the handset unit acquired from Siemens led to a record loss for 2006.