Sony Life Insurance Co. has become the first life insurer in the nation to establish a system offering special holidays for employees donating bone marrow, officials of the firm said Wednesday.

About 700 of the company's 4,300 sales staffers attended a special session on bone marrow transplants, which are given to people with serious blood diseases, said Urara Cavanagh, a Sony official in charge employee education programs.

The Tokyo-based midsize life insurer, wholly owned by Sony Corp., introduced the holidays to encourage its employees to register as marrow donor candidates to contribute to society, she said.

There is no time limit for special donor leave as long as hospitalization is deemed necessary by a doctor, according the firm's spokesman Soichi Hayashi.

Kenichi Hanioka, general manager of the Japan Marrow Donor Foundation, welcomed the move, saying it is believed to be difficult for companies to set up special leave systems amid the economic slump.

A bone marrow transplant, an established treatment with a history of nearly three decades, is considered the most effective course of action for about half of those with such fatal blood diseases as leukemia and hypoplastic anemia.