High-speed communications chipmaker Broadcom (BRCM) was down 9.8% in early afternoon after Morgan Stanley Dean Witter analyst Mark Edelstone lowered his revenue and earnings estimates.

Edelstone also cut estimates for six other semiconductor companies. Affected are:

Agere

(AGR.A)

, trading down 7.1%;

Cypress Semiconductor

(CY) - Get Report

, down 6.8%;

National Semiconductor

(NSM)

, down 5.4%;

PMC Sierra

(PMCS)

, down 10.3%;

Rambus

(RMBS) - Get Report

, down 6.2%; and

Texas Instruments

(TXN) - Get Report

, down 7%.

Edelstone in a note told investors that this economic downturn could be one of the worst in the 25-year history of the semiconductor industry.