"The world has changed," said a Bosch spokesman, adding that there is no longer any business justification for the German automotive supplier's equity holding in Denso.

Bosch acquired a 5.4 pc shareholding in Japan's biggest automotive supplier in 1954 because it wanted to get access to the local market and do business with Japanese automakers.

As Bosch grew globally and established its own presence in every market, it became less dependent on Denso. In 2009, the German supplier group reduced its shareholding to 5.25 pc and this week it announced that it had sold the remaining 46 million shares for 1.1 billion euros.

Despite the obvious competition between two of the world's largest automotive suppliers, the companies continue to cooperate in selected areas. Bosch and Denso, for example, operate a fuel pump joint venture, AFCO, in the US and jointly develop car infotainment systems in Japan and Germany. That venture, which was established in 2003, is called ADIT. The two suppliers also have various licensing agreements.

Bosch CFO Stefan Asenkerschbaumer said the two companies would continue to cooperate in existing joint ventures and alliances. He also didn't rule out future new joint initiatives.

"For nearly 60 years now, the two companies have been cooperating in the automotive supply industry. The basis of this successful cooperation has always been mutual trust and the common desire for excellent technical solutions," he said.

Bosch said it would use the proceeds of the share sale to finance acquisitions and invest in future-oriented technologies.