The current strength of 7.5% will be reduced to 5.5% in May.
Mark Gerken, off-trade sales managing director, said: "White cider continues to attract a high level of negative media and government attention."
The abv would not return to 7.5% in the future, he said.
The company said that white cider represents a very small and declining percentage of the cider industry.
It admitted that white cider was often seen as a "problem drink", but added that those who enjoyed it responsibly would not object to the lower strength.
Gerken added: "While it would be very easy for us to stop producing White Lightning, we recognise that this approach leaves both customers and consumers with only cheaper alternatives.
"Having spent a number of years attempting to lead the way towards a more responsible approach to white ciders, we feel that the time is right to offer
a more responsible alternative."
The latest news follows S&N's removal of all extra-fill promotions and 3-litre packs in 2004.