Aug 16 (Reuters) - S&P Global Ratings on Thursday said that increased regulatory scrutiny of Australia’s infrastructure sector could dampen financial returns.

The regulatory activity would weigh most on equities but could also impact credit quality, the ratings agency added.

S&P said heightened regulatory focus on pricing and service delivery in infrastructure would be an important feature of the market over the next five years. It noted, for example, that scrutiny of privately operated toll roads is on the increase.

Concerns raised by Australia’s competition regulator have threatened a bid by the country’s number one toll road operator Transurban Group for 51 percent of the country’s biggest transport infrastructure project, a A$16.8 billion ($12.21 billion) tollway through the middle of Sydney.

Under pressure from the regulator, it agreed last week to share comprehensive traffic data for all toll roads in New South Wales, where Sydney is located, to alleviate concerns that it has an unfair advantage over rivals.

Meanwhile, regulatory concerns about rising gas prices could also thwart a proposed A$12.98 billion takeover of Australia’s top gas transporter APA Group by Hong Kong’s CK Infrastructure Holdings Ltd. ($1=1.3765 Australian dollars) (Reporting by Aditya Soni in Bengaluru; Editing by Neil Fullick)