Standard & Poor's downgraded Nokia by one notch to B+, from BB-, on Friday, citing pressure on the company's net cash following its agreement to take over Siemens' 50% stake in Nokia Siemens Network.

"We now anticipate Nokia's net cash could be as low as 1.3 billion euros at the end of 2013," S&P said.

The stable outlook assumes a significant reduction in cash losses and gradual market share improvement, S&P said.