Shares in Ericsson, which owns half the joint venture, rose 4 percent on the Stockholm exchange after the leak.
Business is improving for the mobile maker after several crisis years. The company, which had been making losses in the billions of kronor, is now making ever larger profits.
The figures show the company made a third quarter profit of €433 million before tax, or roughly 4 billion kronor. The figures represent an increase in income of 187 percent compared with the same period last year, and is far higher than most analysts expected.
Sales increased to €2.9 billion, compared to expectations of €2.4 billion. The company delivered 19.8 million mobile handsets in the third quarter, compared to the 16.6 million analysts had expected. The company judges that it now has a world market share of 8 percent.
The company has snatched market share from rivals in the sale of advanced models, such as those featuring music players and cameras. This segment has been particularly profitable for Sony Ericsson, although it has complemented its product portfolio with cheap, basic models targeted at developing countries.
Åse Lindeskog, head of press relations at Ericsson, said that human error was to blame for the early release of the figures.
“The wrong distribution list was used by mistake, and an external person got the figures. We then decided that we might as well release them,” she told news agency TT.