Sony is planning to restore its online PlayStation Network (PSN) in full by the end of May.
The company shut its online video game network on 20 April, after discovering a major security breach.
Spokesman Satoshi Fukuoka admitted the company had missed a self-imposed deadline of restarting a partial service by the weekend.
He said Sony continues to investigate the case, after personal details from 100 million accounts were compromised.
The company had originally hoped to restart some of the services on the PSN last week.
However, it then emerged that another large network - Sony Online Entertainment (SOE) - had also been compromised, potentially putting a further 25 million accounts at risk.
This is in addition to the 77 million accounts hacked on the PSN.
The discovery was a major set-back in the company's attempts to get the networks up and running again.
"We were unaware of the extent of the attack on Sony Online Entertainment servers," Sony's Head of Communications Nick Caplin wrote in a blog post.
"We are taking this opportunity to conduct further testing of the incredibly complex system."
'Frustrated and upset'
The extended downtime is causing headaches for businesses which rely on the PSN as a key distributor of their content.
Christian Svensson, Senior Vice-President of Capcom, shared his irritation with users on the Capcom-Unity forum.
"I'm frustrated and upset by it for a number of reasons," he wrote.
"As an executive responsible for running a business, the resulting outage [is] obviously costing us hundreds of thousands, if not millions of dollars in revenue that were planned for within our budget.
"These are funds we rely on to bring new games to market for our fans."
He said the knock-on effect of the hack makes it "impossible to be sympathetic to their 'cause'".
War of words
The latest announcement comes after a war of words with hacker group Anonymous over who is responsible for the attack.
The collective has suffered its own hacking issues after one disgruntled user known as "Ryan" apparently attacked the Internet Relay Chat channel used by the group to co-ordinate its activities.
A list of usernames and corresponding IP addresses has been published by "Ryan" on the AnonOps site.
In a letter to the US Congress last week, Sony accused "leaderless" Anonymous of orchestrating a distributed denial-of-service (DDoS) attack at the same time the data theft occured.
Sony claimed a file planted on the network bore the trademark Anonymous "We are legion" slogan.
The group retalliated, describing Sony as "incompetent".
"Whoever broke into Sony's servers to steal the credit card info and left a document blaming Anonymous clearly wanted Anonymous to be blamed for the most significant digital theft in history," the statement read.
Last month, US lawyers filed a lawsuit against Sony for negligent protection of personal data and failure to inform players in a timely fashion that their credit card information may have been stolen.
Mr Fukuoka declined to comment on the lawsuit.