Oil prices fell almost $9 a barrel on Friday to their lowest level in more than a year as the slowing global economy led the International Energy Agency to cut its forecast for global demand.

Crude oil for November delivery settled down $8.89, at $77.70 a barrel, the lowest since October 2007.

The decline came after the energy agency, which is based in Paris, cut its forecast for 2008 global demand by 240,000 barrels a day. The agency now estimates daily demand this year of about 86.5 million barrels, an increase of 0.5 percent from last year  the slowest growth in 15 years. It also cut its forecast for 2009 demand by 440,000 barrels a day, to 87.2 million barrels, a 0.8 percent increase over this year’s demand.

Prices for commodities soared in the first half of the year, with crude oil prices peaking at $145.29 a barrel in July. But the financial crisis and the accelerating slowdown have pushed prices down.