Sony and Ericsson have been talking for weeks concerning the future of the venture because the companies' 10-year-old pact is actually up for renewal this month, two industry sources informed Reuters.
The Wall Street Journal said the talks were ongoing and could break apart anytime.
Ericsson and Sony declined to comment on the documented talks. "We have a long-term commitment to our combined ventures, " said an Ericsson spokesman.
Many analysts say Japan's Sony must assert control over Sony Ericsson if the venture would be to recoup market share in the cut-throat world of mobile phones.
The joint venture, formed in 2001, thrived after it's breakthrough with Walkman music phones and Cybershot cameraphones, both which leveraged Sony's brands.
But it lost out to bigger rivals Nokia and Samsung Electronics in the cheaper end of the market, and was late to respond to Apple's entrance into the high-end of the market.
It's refocused its business to make smartphones using Google's Google android platform, but it has dropped to the ninth slot in global cellphone rankings from the fourth-highest just a couple years ago.
It is making some progress and turned a net profit of 90 million euros this past year after booking a loss of 836 million in '09. But it reported another loss for the April-June one fourth.
The venture is due to report its September one fourth results on October 14.
Divorce good for both companions?
"A buyout would make a lot of sense for Ericsson when i believe their share in the joint venture is worth for them between zero and minus 1 billion euros, " stated Bernstein analyst Pierre Ferragu.
"Whatever price they agree upon, it would be a positive for Ericsson, " he or she said.
Shares in Sweden's Ericsson gained on the statement and closed 6% higher at 69. 20 crowns upon Thursday.
A full takeover of the venture would increase Sony's overall offering, which includes content, gaming devices, gadgets and even tablet computers. But the company still lacks its smartphones.
"The buyout allows Sony to move development in-house as well as better integrate other products like gaming into newer cell phones, " said Steven Nathasingh from US technology research organization Vaxa Inc.
Last month at the IFA trade reasonable in Berlin, Sony Ericsson's phones were presented inside the actual Sony hall, mixed with Sony's TV sets and brand new tablets.