Investment group International Public Partnerships (INPP) said it had increased the size of its debit facility from £175m to £300m.The FTSE 250 group said that the new facility, provided by Royal Bank of Scotland and National Australia Bank, will expire in 2018, while the old facility was due for renewal in December 2016.INPP added that the cost of the facility was "substantially" lower, having been cut to 175 basis points over the London Interbank Offered Rate, compared with 225 basis points over Libor on the previous agreement."The increase to £300m will support the strong pipeline of new projects over the next 12 months, particularly greenfield projects whereby bids are required to be fully underwritten at the time of submission," the group said in a statement on Tuesday."As such the facility is intended to provide the company with the flexibility to invest in appropriate opportunities rather than serving as long-term, structural leverage."INPP shares were up 0.18% to 137.95p at 09:57 on Tuesday.