Sony's CEO has spoken out about the company's joint venture with mobile phone maker Ericsson, saying the Sony Ericsson brand must do better if it is to survive.

When asked if Sony was considering ending the partnership between the two companies, Howard Stringer told German newspaper Die Welt: "It's certainly been a difficult year but buying out a partner is never an easy thing".

Sony's difficult year so far has been mirrored in the company dropping its group net profit forecast for this year to March 2009 by 17%. It cites the Sony Ericsson slump as a reason for this, as well as tough price competition on its electronics division.

Speaking of the future for the partnership, Stringer said: "We have to work together again as we did two years ago. Or the joint venture will have to find its own solution".