Residential real estate agents in the western part of the country, including Oregon, earned the biggest average commission on home sales in 2008 and beat the national average, according to a study released Monday.

Sold homes in the West also had the largest average selling price by region of $312,100, the study said.

The sales commission study, by ForSaleByOwner.com, showed Western agents earned an average commission per home of $16,230. Average commissions in other regions for last year were: Northeast, $15,500; South, $11,050; and Midwest, $9,540.

Started in 1999, ForSaleByOwner is a Web site for homeowners who want to sell their homes themselves, without the help of a real estate agent. The site competes with agents, providing home-sale services such as advertising and real estate resources for fees ranging from $89 to $899.

Nationwide, total agent commissions on residential sales dropped $12 billion to $46.6 billion in 2008 from $58.4 billion in 2007, according to the study.

In the last eight years, the high for commissions was $71 billion in 2005, and commissions have declined each year since then.

The national average commission for last year was $12,600, down from $13,780.

Average selling prices for homes last year, by region, were: West, $312,100; Northeast, $297,900; South, $212,400; and Midwest, $183,400.

Data for the Web site’s study on agent commissions came from the National Association of Realtors and home-sale data provider Real Trends Inc.