Media giant Associated Newspapers has launched its free paper London Lite, signalling the start of its freesheet battle with rival News International.
The new papers will target young commuters
Thelondonpaper, News International's new title, is set to debut next week.
Both titles will have a print run of about 400,000 copies, and will rely on advertising revenues to make money.
The afternoon freesheets will be targeted at younger commuters who get much of their news from websites and do not expect to pay for a newspaper.
London already has two free morning papers - Metro and City AM - while the Manchester Evening News is now distributed free.
Metro, which is produced by Associated Newspapers, was launched in 1999 and distributes 1.1 million copies a day across London, the Midlands, the North West, the North East, Yorkshire and Scotland.
It is estimated to make a profit of about £8m a year.
With the launch of London Lite, Associated will be targeting Metro's young commuter readership with an afternoon offering.
"All the other titles are targeting this market," said Steve Auckland, who heads the company's Free Newspaper Division.
"They are low watchers of TV and are not big listeners to radio as well so it's about being able to reach that market well.
"If you can target this market as well as we have shown with Metro you can charge a reasonable rate for advertising and consequently make a profit out of the business."
Associated Newspapers publishes paid-for titles the Daily Mail and Evening Standard, while media mogul Rupert Murdoch's News International produces the Sun and the Times.
All these titles could lose readers because of the new freesheets, but they have little choice, according to media commentator Roy Greenslade.
"If your paid-for titles are going down, and sales are plunging, then you have got to come up with another delivery method, and freesheets are it," he told BBC News.
He said that News International had decided to take the gamble of launching its own free title when it saw that Associated's Metro was making money.
"Associated Newspapers, which owns the Evening Standard and Metro, now has to defend the territory it already has because Rupert Murdoch has decided that he wants a piece of the action."
The Manchester Evening News started giving away 50,000 copies in the city centre last April in a bid to tackle 40 years of declining circulation.
Speaking to the BBC about the move, Mark Dodson, the regional division chief executive of the paper's publisher, Guardian Media Group, said the decision was one many other regional evening newspapers would have to make.
"We took the rate of circulation decline and extrapolated it forward and realised we would sell our last copy in 2025. That was quite unacceptable.
"The consumer is in charge now. They are dictating how and where they get their information and we have to react to their demands and fit in with their lifestyle."