Maeda Road said separately that it wants to cancel a capital alliance with Maeda Corp, its top shareholder, and buy back all of its shares held by Maeda Corp.

The announcement of Maeda Corp's bid was made without official contact, Maeda Road said in a statement.

"We will try to persuade Maeda Road management to agree with our plan," Maeda Corp President Soji Maeda told at a media briefing, adding that Maeda Road has not agreed with Maeda Corp's attempt.

Unsolicited bids are uncommon in Japan, where many companies are shielded by cross-shareholdings to protect management.

But a handful of companies have attempted to launch such bids lately as shareholders have become more vocal about getting higher returns and as the domestic market shrinks.

Maeda Corp plans to increase its stake in Maeda Road to 51% from 24.68% through a public tender offer starting on Tuesday, citing the need for strengthening collaboration to better respond to labour shortages and ageing infrastructure.

Maeda Corp will pay 3,950 yen ($35.86) per Maeda Road share, 26% premium to Maeda Road's close of 3,135 yen on Monday and 50% premium to Friday's close of 2,633 yen.

Maeda Corp's announcement was made before the market close in Tokyo.

Maeda Corp's bid follows an attempt by an optical products maker Hoya Corp to buy NuFlare Technology Inc, a maker of chip-making equipment partially owned by Toshiba Corp, which Toshiba tried to take over.

Hoya did not launch the bid in the end as Toshiba last week succeeded with its bid even though Hoya's price was higher that Toshiba's offer. [nT9N28L00A]

(Reporting by Junko Fujita and Ritsuko Shimizu, editing by Louise Heavens)