The bank slashed its 2016 price forecast for Brent crude to $36.25 per barrel from $58.00 earlier, while lowering its 2017 outlook to $54.25 per barrel from $65.

It also cut its 2016 WTI crude price outlook to $37.75 per barrel from $56.44, and for 2017 to $54.25 from $63.31 per barrel.

The Swiss bank, however, said prices were likely to converge back to the $60 per barrel levels required to grow American shale in the next few years.

Oil dropped to $30 a barrel on Tuesday, trading within sight of a 12-year low on concerns about excess supply and more signs of a Chinese economic slowdown.

(Reporting by Vijaykumar Vedala in Bengaluru; Editing by Hugh Lawson)