Kokuyo, despite Pentel resistance, took a 37% stake in Pentel earlier this year with the help of a third-party fund, Mercuria Investment Co Ltd.

Such a move is rare in a country where deals tend to be driven by consensus. But a push for better corporate governance and a shrinking domestic market have recently spurred some hostile bids including trading house Itochu Corp's successful takeover of sportswear maker Descente.

Kokuyo said the combined company would be better positioned to compete domestically and to expand globally. It was prepared to spend over 3.842 billion yen ($35.22 million) to buy the unlisted shares, it said.

A Pentel spokeswoman said the company's position was not yet decided.

"It was an unexpected announcement, and we are currently examining the contents and considering," she said.

($1 = 109.1000 yen)

(Reporting by Ritsuko Ando; Editing by Mark Potter)