The management fees paid by New York City's public pension funds surged 28 percent in the last fiscal year, according to the comptroller's annual report.

For the fiscal year that ended in June, the report said, the five funds that cover the retirement benefits for city employees and teachers paid $472.5 million in fees to private fund managers. That was $100 million more than the previous year. The funds assets rose by 12.1 percent to $137 billion at the end of the fiscal year. Last month, Liu said the assets had climbed to $144 billion.

Public pension funds across the country have come under increasing pressure as actuarial assumptions about return on investment have been lowered, widening the gap in future unfunded liabilities. New York City's liabilities were pegged at $77.3 billion in a Morningstar report this month. That was by the highest amount faced by any large U.S. city.