International Public Partnerships Limited (INPP), the listed infrastructure investment firm, has announced that it has acquired the remaining 25% interest in the Northern Diabolo Project not already owned by it from HSH Nordbank.

The opportunity to make the additional investment has arisen through the pre-emptive rights that were obtained when INPP acquired its 75% interest in 2007. The additional 25% stake was acquired for €33.3 million (£28.1 million).

The Northern Diabolo Project is a Belgium-based project that provides improved rail access to Brussels airport. The Project involved building and financing a rail link over a five year construction period and thereafter maintaining if over a concession period of 35 years.

The construction programme, overseen by Amber Infrastructure (INPP's investment adviser), was successfully completed on time and to budget on 25 February 2012, saw a new tunnelled rail connection under Brussels airport runway, linking the airport to the new Brussels-Antwerp High Speed rail line.

INPP said that the project meets all its investment criteria and has a number of attractive features including:

• Provides immediate yield to investors
• High level of familiarity with the Project given the Company's existing investment and that the Investment Advisor has been involved from Project's inception
• Long duration asset with c. 34 years remaining on the scheduled life of the concession
• Project revenues which are linked to future inflation
• Limited construction risk given that the Project entered into operational phase in 2012 and the transition to full operations continues successfully
• The transport exposure in INPP's portfolio is increased from 21% at 30 June 2103 to 24%. The revenues receivable by INPP from the Diabolo project are based on an indexed fixed fee basis and with part of the revenues being dependent on passenger throughput but with protective downside mechanisms.

INPP said that the acquisition will be funded through INPP's existing cash resources.

Keith Dorrian, Chairman of International Public Partnerships, said:

"INPP is delighted to have acquired the remaining interest in the Diabolo Project. The opportunity is evidence of the value of the pre-emption rights that exist within the INPP portfolio and the benefit in developing 'home-grown' opportunities.