The London Evening Standard is to become a free newspaper.
About 600,000 copies of the paper - which currently costs 50p - will be given out in London from 12 October. Current circulation is about 250,000.
The move follows Russian billionaire Alexander Lebedev taking control of the Standard from Daily Mail-owner Associated Newspapers in January.
The London Lite paper is already given away free. Last month, the free London Paper ceased publication.
Industry sources suggested that the Lite, owned by Associated and with a circulation of about 400,000, would eventually close or merge with the Standard, leaving just one daily evening paper in the capital.
Standard editor Geordie Greig said his paper would "wait with eagerness" to see how the management of the Lite responded.
The Standard becoming a freesheet goes against the stance of News International - publisher of The Sun and The Times, as well as the Wall Street Journal.
It has signalled an end to free news, saying it would start charging online customers for news content across all its websites, in addition to closing the London Paper.
The Standard, which is 75.1% owned by Mr Lebedev and 24.9% owned by Associated, has been a paid-for product for more than 180 years.
Mr Lebedev said that the Standard was "the first leading quality newspaper to go free".
"I am sure others will follow," he added.
Mr Greig, installed after Mr Lebedev gained control of the paper, described the move as a "historic moment and great opportunity".
"The Standard has an exciting and secure future with this new, pioneering strategy of more than doubling our distribution," he said, which would make it a "one stop shop" for display and classified advertising.
Managing director of the London Evening Standard Andrew Mullins said that it had been a challenge to sustain a paid-for newspaper - even before free afternoon newspapers were launched in 2006.
"There are so many competing distractions to potential readers, particularly with new technologies. Being a quality newspaper with large scale and reach should transform our commercial fortunes," he added.
Associated also prints the free Metro paper - distributed in London and several other UK cities.