MTR (HKG:0066) could potentially pursue more debt funding over the next three to five years due to a string of planned investments, S&P Global Ratings said in a recent release.

A rise in debt issuance amid greater primary residential transaction volume, along with controlled financial management, should anchor the Hong Kong-based metro operator's financial framework, S&P said.

The increase in investments will come as the company sees flat operating cash flow, S&P said.

The company's latest capital expenditure budget was at HK$82.6 billion over the next three years, which could potentially raise annual spending more than the figure in 2025, the rating agency said.

Negative reversion rates will continue to constrain the company's Hong Kong station commercial businesses and property rental and management segments, according to S&P.

The rating agency also sees the company's ratio of funds from operations to debt to face headwinds from greater spending amid steady cash flow.