The $3bn acquisition, if agreed, would represent the latest in a series of acquisitions and mergers seen among the world's leading chip makers.
In a statement Renesas said it was looking at various options to grow the business and alluded to a possible deal with a U.S. chipmaker, although it said that nothing had yet been decided. Last year the company revealed that it had allocated several billion dollars for possible acquisitions. Intersil has yet to comment.
Renesas was the world's third-largest chipmaker by market share at the end of 2015, with 9.1 percent, according to market analysts Gartner.
Markets reacted to the news with Renesas shares rising by over 4 percent in early trading before finishing 3.1 percent lower when markets closed in Tokyo.
Intersil currently has a market capitalisation of $2.1 billion and, according to sources, Renesas is looking to use cash on hand and could also consider borrowing funds to finance the acquisition which could be concluded as early as this month.
