(ShareCast News) - Mixed-use property regeneration specialist U+I, along with a controlled affiliate of global real estate and investment management firm Colony NorthStar announced the creation of a joint venture platform to invest in the London City Region, Manchester and Dublin office markets on Wednesday.The partners will each own 50% of the joint venture, adding value to underperforming office buildings through improved planning, development, refurbishment and asset management.U+I said the partners have both made substantial resource and capital commitments to the new platform, which is expected to deploy approximately €300m over the next investment period.The company has made an initial capital contribution of €14m, and seeded the joint venture with two assets - The Record Store at The Old Vinyl Factory in London, and Donnybrook House in Dublin.It said the Record Store is being repositioned to create 60,000 sq ft of creative office space as part of U+I's wider transformation of the 17-acre site, while Donnybrook House is a 72,000 sq ft vacant building in a prominent location in central Dublin which U+I will refurbish to meet the demands of creative and tech focussed businesses.Most recently Ballymoss House - a 67,000 sq ft third generation office building - has been acquired in Dublin for €13.5m and will be immediately refurbished."We're delighted to be partnering again with Colony NorthStar," said U+I chief executive Matthew Weiner."The specialist platform will target opportunities to develop high quality office space where there are limited options for new build."Weiner said there is currently a shortage of offices across U+I's core locations which provide the right space or environment to satisfy the needs of modern enterprises."Office refurbishment is one of U+I's core skills, this platform will allow us to deliver workplaces tailored for the 21st century and create value through our expertise in planning, development, refurbishment and asset management."Stefan Jaeger, managing director at Colony NorthStar, said his company was excited to broaden its existing relationship with U+I, which it regards as "best-in-class partners", to the strategic specialist platform."With a high-quality portfolio of seed assets and a strong pipeline in markets with attractive fundamentals, we look forward to creating a preeminent portfolio of Grade A office space and leveraging Colony NorthStar's expertise in the creation of scalable platforms."