The deal was first proposed in November last year

Panasonic has completed its purchase of a 50.2% majority stake in Japanese electronics rival Sanyo.

The conclusion of the 403.8bn yen ($4.6bn; £2.8bn) deal comes 13 months since Panasonic first announced its interest in the deal.

Analysts said Panasonic was most interested in Sanyo's manufacture of hybrid car batteries, a field in which both firms are strong.

Shares in Sanyo closed up 11% before Thursday's announcement.

Significant profit

While Panasonic runs a joint venture with Toyota to produce hybrid car batteries for Toyota's Prius model, Sanyo makes similar batteries for Honda, Ford and Peugeot Citroen.

Sanyo is also a leading producer of solar panels.

Panasonic is paying 131 yen for each common Sanyo share it has bought, handing a significant profit to Sanyo's three main shareholders - US investment bank Goldman Sachs, and Japanese firms Daiwa Securities and Sumitomo Mitsui.

They bought their collective 70% stake in Sanyo in 2006, at a price of 70 yen per share.

Financial loss

Despite Sanyo's success in the manufacture of car batteries, it has faced problems in recent years in its consumer products division.

As a result it has cut thousands of jobs, and sold off unprofitable operations.

Recently Sanyo - which is more reliant upon exports than Panasonic - has been hit by the strength of the yen and rising material costs.

It was also forced to change its top management after an accounting scandal over falsifying past earnings.

Sanyo's most recent financial results showed that it made a net loss of 30.6bn yen in the half-year to the end of September, compared with a 8.7bn yen profit a year earlier.