Tech ratings changes: Sony, iRobot, Rackspace, Red Hat, AOL

|About: Sony Corporation (SNE)|By:, SA News Editor

Sony (SNE +0.8%) has been upgraded to Buy by Jefferies a day after announcing (along with its FQ3 results) the sale of its PC unit, and plans to spin off its TV ops.

iRobot (IRBT -3.2%) has been cut to Underweight by JPMorgan a day after rallying in response to a Q4 beat and mixed guidance.

Rackspace (RAX +2.3%) and Red Hat (RHT +2%) have been started at Outperform by Credit Suisse. Rackspace reports on Monday.

AOL (AOL -2.4%) has been cut to Neutral by BofA/Merrill and Macquarie following yesterday's Q4 beat.

Teradata (TDC -2%) has been cut to Underweight by Morgan Stanley a day after beating Q4 estimates and offering soft EPS guidance.

Mobile TeleSystems (MBT +1.1%) has been upgraded to Overweight, and Vimpelcom (VIP +0.5%) to Equal Weight, by Barclays. Credit Suisse upgraded MTS on Wednesday.

SBA (SBAC -1.1%) has been cut to Neutral by Citi. Q4 results arrive on Feb. 26.

21Vianet (VNET -0.3%) has been cut to Neutral by Credit Suisse.