Updated from 2:52 p.m. ET

Shares of auto-parts suppliers traded lower on Tuesday as Wall Street issued downbeat opinions on several companies, citing the downturn in automobile demand.

Standard & Poor's Equity Research analyst Efraim Levy downgraded shares of

Johnson Controls

(JCI) - Get Report

to hold from buy, in a note to investors on Tuesday. Levy said the company's earnings would be weakened by deteriorating auto demand.

Separately, credit ratings agency Moody's Investors Service cut several of its ratings on parts maker


( ARM), while S&P Ratings Services cut its credit ratings on


(TEN) - Get Report

Parts suppliers have been battered recently by the downturn in global vehicle sales, as automakers slash production and buy fewer automobile parts. Their shares mostly declined in afternoon trading. Johnson Controls fell 56 cents, or 3.1%, to $17.78. ArvinMeritor fell 15 cents, or 5.0%, to $2.87. Tenneco was down 13 cents at $2.41.

Shares of


(BWA) - Get Report

declined 95 cents, or 4.3%, to $21.14.

American Axle & Manufacturing Holdings

(AXL) - Get Report

lost 34 cents, or 13.44, to $2.19.

TRW Automotive Holdings


was unchanged , to $3.45.