Glendale-based Public Storage, the largest storage operator in the world, reported lower third-quarter earnings but rising revenue and profits from core storage operations.

Total net income for the quarter fell 35 percent to $118 million or 69 cents per diluted share, compared with $182.2 million, or $1.07 per diluted share in the year-ago quarter.

The decline was due primarily to a foreign currency exchange loss of $28.3 million for the quarter, compared to a gain of $55.5 million in the year-ago quarter.

The loss was offset by improved operations. Revenue from the company’s 1,931 facilities increased 5.3 percent to $390 million this quarter. Occupancy rates at storage facilities increased by 1.3 percent while realized rent per occupied square foot increased 4 percent.

Costs associated with operating those facilities stayed flat at $120.5 million, giving storage operations a profit of $269 million, up 9 percent from the third quarter of 2010. The storage facilities had a gross profit margin of 69 percent.

The company said average occupancy rates were 92.2 percent, up from 91 percent a year ago.