BT had been given a July 1 deadline to ensure its network services were up to scratch.
BT has confirmed it suffered a major network outage over the weekend, shortly before the company was facing a deadline to improve the reliability and standards of its broadband network.
Ofcom had stated on Friday that it had given BT a deadline of July 1 to ensure its Openreach service would be able to satisfy new performance standards in line with new regulations, which had been ratified by the European Commission.
These include making sure that at least 70% of any phone and broadband faults will be repaired within two working days, and at least 55% of customers requiring a new line must receive an appointment within 12 working days. Both of these figures will rise to around 80% by 2016.
Should Openreach, which also supplies connections to BT's network on behalf of competing providers, fail to meet the new targets, which form part of the watchdog's Fixed Access Market Reviews, BT will face sanctions from Ofcom, which could include fines, the watchdog warned.
Over the weekend, however, many BT customers across the UK reported they were unable to connect to the internet and access many popular websites, including social media, banking and shopping pages, as well as BT's own website, meaning users were unable to contact the provider for help.
The outage on Saturday hit customers from areas including Cornwall, Eastbourne, Preston, Tunbridge Wells and several other areas were affected.
BT said: "This is in no way linked to the new service levels from Ofcom which come into force for our Openreach business on 1 July. The cause was a network incident and it was resolved within around two hours."
"We're sorry for any trouble this may have caused," a BT spokesman said, although the company was unable to say how many of its seven million broadband customers had been hit by the issue.
A message posted on Twitter on Saturday by BTCare said: "Sorry about the issues many of you had accessing the Internet this morning. Problem is now fixed- sorry for any trouble caused."
As part of Ofcom's new regulations, Openreach will also have to publicly report on its performance going forward, publishing quarterly reports on its website from October at the latest, which Ofcom says must provide, "clear, meaningful and transparent information" about how long Openreach is taking to repair faults and install new lines.
Last month, BT announced it would be hiring 1,600 more engineers following severe criticism from the watchdog concerning unrepaired faults and slow Internet installation.
Source: Company Press Release