(Changes source, adds analyst comments and share movement)
Jan 7 (Reuters) - Bear Stearns downgraded Best Buy Co Inc (BBY.N) to "underperform" from "outperform," citing a slowdown in product cycle with the resulting pressure on sales and margins, and the likely shift in market share to discounters.
Bear Stearns' analyst Christopher Horvers noted that revenue growth at Best Buy was most correlated to gross domestic product, industrial production and real disposable income growth.
"Given recent macro data, including worrisome trends in payroll reports, this sector is positioned poorly in such an environment," he added in his note to clients.
Hovers also said that factory sales of electronics are expected to almost half to 6 percent in 2008.
In addition to the slowdown, a negative mix shift in margins is occurring with increased sales of lower margin products and lower sales of higher margin products, he added.
Shares of the top U.S. consumer electronics retailer were down more than 2 percent at $46.60 in pre-market trade, after closing at $47.61 Friday on the New York Stock Exchange.
(Reporting by Tenzin Pema in Bangalore; Editing by Himani Sarkar)