Nvidia Taken Down a Notch at Morgan

NEW YORK (TheStreet) -- The chip sector got a big round of downgrades from Morgan Stanley on Tuesday on concerns that supplies are catching up with demand.

Nvidia (NVDA Quote) got one of the most negative rating cuts of the group. Morgan Stanley, forecasting greater challenges as the company shifts more of its business from PCs to portable and mobile devices, lowered its rating from neutral to sell.

In addition to the hurdles in the new markets, Morgan Stanley sees stronger competition from AMD (AMD Quote) and Intel (INTC Quote), as the PC processor duo aims at Nvidia's graphics processor sweet spot.

Morgan Stanley also put sell ratings on ON Semiconductor (ONNN Quote) and ArvinMeritor (ARM Quote) and neutral ratings on previously buy-rated chip stocks Tuesday including Intel, Altera (ALTR Quote), Micron (MU Quote) and Xilinx (XLNX Quote).

The analysts did hand out two upgrades in the chips group. Morgan Stanley raised Linear Technology (LLTC Quote) and Maxim Integrated (MXIM Quote) to buy from neutral.

Nvidia shares were down 3% to $11.65 in premarket trading Tuesday.