As the country's population rapidly greys, phone companies, recognising the sometimes life-saving function of mobile phones, are increasingly targeting older Japanese, the Asahi Shimbun reported.

They are offering models with bigger screens and larger font sizes, better audibility and easier-to-operate keys, the newspaper said.

The top three telcos, NTT DoCoMo Inc, KDDI Corp and Softbank Mobile Corp, even offer free talk time for members of a family as long as they all subscribe to the same company's services.

All three also offer classes to help elderly users understand their products, said the Asahi.

At one such class on text messaging last month in Tokyo, sponsored by KDDI, the nine participants ranged in age from 55 to 82.

Madam Namie Tsuruta, 70, said her daughter had asked her to get a mobile phone because she had just moved to a new house.

'My daughter is worried about me living alone, so she told me to make sure I have a mobile phone,' she was quoted by the Asahi as saying.

She added, with a laugh, that it took her 10 minutes to type in 'Genki?' (How are you?) before calling the recipient to make sure her message had arrived.

On her mobile phone, she has saved three phone numbers - those of her daughter, son and daughter-in-law - so that she could reach any of them by hitting just one key, the Asahi reported.

At a recent class held by NTT DoCoMo, one of the participants, a 73-year-old woman, said she had not planned to own a mobile phone but bought one after her husband suffered cerebral infarction, a blockage of blood flow in the brain.

Although he recovered, she thought a mobile phone would be handy to keep in touch with him when they were apart, the Asahi reported.

The combination of real need and marketing savvy could explain the high penetration rate of mobile phones among older Japanese.

Sixty per cent of Japanese in their late 60s now use a mobile phone. Even among those in their 70s, the rate is more than 30 per cent, the Asahi said, citing a government survey conducted at the end of last year.

And catering to the elderly does not mean form should be traded for function.

Softbank Mobile says it is designing mobile phones for senior citizens that look as cool as those for younger people.