Currently the Editors' Code of Practice Committee consists of 13 editors, but five lay people will join it to review the code.
Its definition of public interest will be revised "with urgency", the committee said.
A review had been suggested by Lord Justice Leveson.
He also recommended that lay people be appointed to the committee.
In future it is proposed the number of editors will be reduced by three, to 10, and five lay people, including the chairman and director of the new regulator, will join as full members, the BBC reported.
In his damning report running into 2000-pages, Lord Justice Brian Leveson said last month that the British press must create a new and tough regulator but it had to be backed by legislation to ensure it was effective.
He said the press had failed to properly regulate itself in the past, but he believed the law could be used to "validate" a new body.
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Leveson had said that the British newspaper industry had "wreaked havoc with the lives of innocent people" and "acted as if its own code, which it wrote, simply did not exist."
He said behaviour of the press "at times, can only be described as outrageous."
Meanwhile, the Editors' Code of Practice Committee also announced that a new "compliance clause" will be added to the code.
It will state that all editors must offer readers a "clear and effective" means of making complaints, and must publish corrections and apologies promptly.
The review will also encourage newspapers and magazines to urge their own readers to contribute to the code review.
It is hoped the proposals will "ensure high standards of journalism in a fast-changing media world", the committee said.
Committee chairman and Daily Mail editor Paul Dacre said: "Lord Justice Leveson recognised in his report that the Editors' Code was praised by witnesses to his inquiry.
"He also recommended improvements - and the committee is determined to meet this challenge as promptly and positively as possible."
British Prime Minister David Cameron had set up the Leveson inquiry last year after it emerged that journalists at the now-defunct News of the World tabloid of Rupert Murdoch had hacked the phone of Milly Dowler, a 13-year-old murdered schoolgirl, as well as targeting dozens of crime victims, celebrities and politicians.