The newsroom and template will allow Bright One, which is a communications agency for the third sector, to create, distribute and promote its news via the Pressitt platform.
Pressitt will help the not-for-profit organisation make its news announcements more "social" through social bookmarking, commenting functionality and web 2.0 shareable features, including audio and video clips.
In addition, Pressitt releases are search-engine friendly so that they will be visible in search results for relevant keywords.
Ben Matthews, founder of Bright One, said: "The nature of public relations has rapidly changed in recent years and the tool of the traditional press release has had to change with it.
"The social media newsroom demonstrates this and we look forward to getting our clients' news out there by using the latest social media tools and engaging with our audiences on a wide range of social media platforms."
Pressitt was launched in March by digital PR and social media consultancy Liberate Media and web development company Best Served Cold.
Lloyd Gofton, director of Liberate Media and Pressitt, said: "At Pressitt we're committed to assisting our partners in communicating in the most useful and relevant way with their communities.
"We are already engaging with a whole host of organisations to deliver tailored responses to their social media news challenges and have seen at first hand the continued growth and understanding of the social media news environment."
Pressitt is offering to build social media newsrooms free of charge for all charitable organisations, with reduced hosting fees.