UPDATE 1-Bel Fuse offers to buy Power-One's DC/DC business

(Recasts, adds details, share movement)

June 13 (Reuters) - Network equipment maker Bel Fuse Inc (BELFA.O: Quote, Profile, Research) offered to buy the DC/DC converters business of Power-One Inc (PWER.O: Quote, Profile, Research), saying the latter would be able to reduce a major portion of its debt with the sale proceeds.

Power-One must divest one or more of its business units to reduce debt, Bel Fuse CEO Daniel Bernstein said in a letter to Power-One's board.

Bel Fuse along with its Bel Ventures unit owns about 5 percent stake in Power-One, a maker of power supply products.

Bel Fuse, which supplies circuit protection devices, power conversion modules, transformers and connector modules, had proposed to acquire Power-One in March, citing similarity in businesses and know-how.

"...the market continues to undervalue Power-One due to its inability to focus on its core business segment of AC/DC power supplies," Bel Fuse CEO Bernstein said.

The DC/DC converters and AC/DC power supplies are analog and digital power management and conversion products for server, communications, military and industrial applications.

Shares of Power-One were trading down about 2 percent at $2.26 in morning trade on Nasdaq. At that price, the company is valued at about $198 million, based on 87.5 million shares outstanding as of May 4.

Class B shares of Bel Fuse were trading up 16 cents at $25.78 on Nasdaq. (Reporting by Bhaswati Mukhopadhyay in Bangalore; Editing by Gopakumar Warrier)