Morgan Stanley raised its rating on Bharti Airtel Ltd to "overweight" from "equalweight," citing positive factors for the sector such as rising tariffs and data volumes, falling capital spending and eased competitive intensity.

Morgan Stanley said the "failure" of the recent 900 Mhz auction also lowered regulatory risk for India's mobile sector, and upgraded Idea Cellular Ltd as part of the same report dated Wednesday.

Nomura also raised its rating on Bharti, but to "neutral" from "reduce", citing a recent share price drop. Nomura said it remained "relatively cautious" on the sector given high valuations, regulatory "drama", and a "low" degree of confidence in earnings.