TOKYO (Reuters) - Japan's Renesas Electronics Corp (>> Renesas Electronics Corporation) is in the final stages of negotiations to acquire U.S. chipmaker Intersil Corp (>> Intersil Corp) for as much as 300 billion yen (2.28 billion pounds), an industry source familiar with the deal said on Monday.

An agreement on the deal, which would be the latest in a trend of consolidation among global chipmakers, was likely to come "soon", said the person, who was not authorised to discuss the matter and thus asked not to be named.

Renesas said in a statement it was considering various options to grow, including a deal with a U.S. chipmaker, but that nothing had been decided. Intersil could not be reached for comment outside business hours in the United States.

Renesas shares rose as much as 4.2 percent in early morning trade before closing down 3.1 percent.

Some investors have doubts about how much the deal could boost Renesas's profits, said Gavin Parry, managing director of Parry International Trading Ltd in Hong Kong.

Renesas Chief Financial Officer Hidetoshi Shibata told Reuters in an interview late last year that the company had earmarked billions of dollars for acquisitions to defend an industry lead under threat from merging peers. He noted that Renesas had over 300 billion yen in cash to fund potential acquisitions.

Intersil had a market capitalisation of more than $2.1 billion as of Friday. Renesas will add a premium to buy Intersil, seeking to take full control of the Milpitas, California-based company, the Nikkei business daily reported earlier on Monday.

Renesas plans to use cash on hand and may also consider borrowing funds from banks, the Nikkei said, adding that the deal could be reached as early as this month.

Slowing growth in computers and smartphones - the traditional mainstays of the industry - fuelled a wave of mergers last year, with chipmakers turning to areas such as auto electronics for sales growth.

Demand for cheaper chips and new products to power internet-connected gadgets has also driven consolidation in the industry.

Worldwide semiconductor M&A topped $80 billion last year, Thomson Reuters data showed.

Renesas was created in 2010 from a merger of NEC Corp's (>> NEC Corp) chip division and Renesas Technology, which itself was established through a merger of the chip units of Hitachi Ltd (>> Hitachi, Ltd.) and Mitsubishi Electric Corp (>> Mitsubishi Electric Corporation).

At the end of last year, Tokyo-based Renesas was the world's third-largest chipmaker by market share, with 9.1 percent, data from technology research firm Gartner showed.

The Japanese company lost its second-place spot after Dutch rival (>> NXP Semiconductors NV) bought U.S. chipmaker Freescale Semiconductor Ltd in a $12 billion deal in December.

(Reporting by Makiko Yamazaki, Chang-Ran Kim and Thomas Wilson in TOKYO and Catherine Ngai in NEW YORK,; Editing by Stephen Coates and Muralikumar Anantharaman)

By Makiko Yamazaki