The deadline was initially set to expire on Thursday.
The delay is intended to give shareholders, such as Air France-KLM, time to look at a new strategic plan which was adopted by Alitalia's board at a meeting late on Wednesday.
Air France-KLM voted against the revised plan according to Italian media reports.
Alitalia said the new plan proposed "reducing the number of medium-range planes, but keeping the number of flights seen in 2013 thanks to a better use of the fleet".
It said it included a "severe reduction of costs".
It also said "the number of international and intercontinental flights will be increased".
There was no mention of possible job cuts in the company's statement.
Italian unions had warned of a tough response if the cash-strapped airline announced it would be axing jobs.
The "decision to delay to November 27th the deadline for subscription to the capital increase" was taken to allow shareholders "to get acquainted with the revised plan," the statement said.
A fresh board meeting has been pencilled in for November 27th, a source who attended Wednesday's meeting was quoted as saying by Ansa news agency.
Major shareholder Air France-KLM, which owns 25 percent of Alitalia, has yet to announce whether it will take part in the €300 million recapitalisation plan to save the Italian airline which is in debt to the tune of €1.2 billion.
Alitalia was already bailed out by taxpayers five years ago in a controversial operation that handed a consortium of private Italian companies a majority stake, part of which was later sold to Air France-KLM.
The still-struggling Italian airline is again flirting with bankruptcy, prompting the hasty recapitalisation plan.
Italian energy group ENI has threatened to ground the fleet of planes by stopping fuel supplies because of unpaid debts.
Alitalia says Italian banks are lined up to lend it €200 million. And the state-owned Italian postal service has been tapped to contribute up to €75 million, triggering rivals' allegations of illegal protectionism.
The Italian government has held out the prospect that another partner could be found if Air France-KLM declines to take part in the recapitalisation plan.
The transport ministry has said that if the French airline does not take part, its stake will fall to around seven percent, opening the door to a possible partner from Asia.