NEW YORK (AP) ¿ Some semiconductor stocks traded lower Friday as a monthslong rally looked set to taper off and an analyst downgraded several companies.

The Philadelphia Semiconductor Sector index declined 1.4 percent on Friday to 272.26 after closing at 285.71 on Monday, its highest finish since Oct. 2.

Citi analyst Timothy Arcuri downgraded four semiconductor-industry stocks from "buy" to "hold": Lam Research Corp., Teradyne Inc., Applied Materials Inc., and ATMI Inc.

Arcuri said a supply correction that had helped semiconductor equipment stocks had mostly run its course, saying supply had caught up to demand in the quarter through June.

He noted that the Philadelphia chip index had already risen 35 percent since the start of the year, compared to a 4 percent gain in the S&P 500.

Shares of Lam were down $1.11, or 4.1 percent, to $25.89; Teradyne was off 33 cents, or 4.4 percent, at $7.15; Applied Materials sank 53 cents, or 4.6 percent to $11.01; and ATMI shares fell $1.32, or 7.5 percent, to $16.28.

Arcuri said he continued to favor FormFactor Inc. because of its strength in the DDR3 memory segment, but removed it from a list of top picks. FormFactor shares rose 9 cents to $19.92.

Intel Corp., the world's largest chip producer, fell 2 cents to $16.11.

Advanced Micro Devices Inc. shares rose 10 cents, or 2.2 percent, to $4.75.
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