Sony has bought full control of mobile phone maker Sony Ericsson from Swedish telecoms equipment maker Ericsson.
The giant Japanese technology company is to buy 50% of the company for 1.1 billion euros ($US1.5 billion), making the mobile handset business a wholly-owned subsidiary of Sony.
Ericsson said that the "synergies" between telecoms equipment and mobile phones were decreasing.
The BBC reports the transaction also includes a patent deal.
Sony wants to integrate the mobile handset business with its mobile games machine and tablet computers.
Chief executive Sir Howard Stringer says the deal will give Sony a foothold in the growing smartphone market.
Sir Howard says the smartphones will be given a new brand, at some point.
Earlier this month, Sony Ericsson broke even in its third quarter and announced it would focus on smartphones from 2012.
The company said its Xperia smartphones accounted for 80% of its sales. The handsets run Google's Android operating system.