Updated from 9:16 a.m. EDT
Applied Micro Circuits
was down sharply after
cut it to buy from strong buy, in part because
is a major customer.
The firm also cited Applied Micro's valuation.
Applied Micro was recently down $56.06, or 28%, to $142.25. The company's shares closed yesterday at $198.31.
Nortel's shares were hammered in after-hours trading Tuesday, following the company's third-quarter earnings report. Nortel posted earnings that beat analysts' estimates by a penny but reported revenue that disappointed Wall Street.