Sony became the largest shareholder of Olympus in September 2012. Since then, we’ve waited for the relationship to lead to more collaboration between the companies.
Olympus recently revealed that it will soon being supplying lens parts to Sony. According to an Olympus spokesperson,
The imaging sensor has already started to source from Sony to Olympus. And the lens [parts] and lens units will start to source from Olympus to Sony.
While Olympus refused to specify the extent of the lens parts supplies to Sony, rumors suggest that Olympus will develop a 400mm f/4 lens for Sony Alpha A-mount cameras to be unveiled in early 2014.