Michael Hill, Trinity's head of multimedia, speaking at the UCEBirmingham citizen journalism conference today, said that the five sites on the Teesside Gazette were launched at the start of the year.
He said 20 volunteers have already agreed to contribute to the sites, which are grouped around postcode areas in Middlesborough.
Mr Hill added that 18 more micro-sites in the town would be launched by July and, if successful, the idea could be rolled out across the group.
He told Journalism.co.uk: "We've set up a content team at the newspaper of people from different disciplines. Someone from the library, a reporter, a former photographer and an employee with IT skills are overseeing what will eventually become 23 sites.
"All the sites are based around postcodes in Teesside and what we have done is populate those sites with local content from the newspaper.
"We're also hosting lots of local content that there was not room for in the print edition, everything you can imagine that is going on in that local area; meetings, news, anything and everything.
"The idea is that it will be totally run by local people and it will just be overseen by the content team.
"We're leafleting libraries, play groups and community centres, getting hold of neighbourhood watch co-ordinators, anybody and everybody that lives in a local area, and asking them to put their news on the site."
Mr Hill added that Trinity Mirror would invest in training to enable local communities to contribute to the sites. Hardware could also eventually be allocated to regular contributors to make it easier to provide stories.
"This is something that could play quite well in lots of other communities. I think this is the sort of idea that we can take anywhere."