Small and midsize radio and television markets in the Pacific region, especially in metro areas with large Hispanic populations, have the greatest growth potential, according to a study of market revenues released Tuesday by media research firm SNL Kagan.

The annual report, “Radio/TV Station Annual Outlook: Market-by-Market Revenue Projections,” examines broadcast revenue trends, demographics and ad revenue forecasts to project market growth over the next five years. It includes factors stemming from the presidential election in determining a market’s potential for this year.

SNL Kagan projects 3.9% growth in television revenues through 2012 despite a drop of 8.5% last year triggered by the writers’ strike and the movement of advertising dollars to the Internet. TV ad revenues are forecast to rise 8.8% this year, factoring in the presidential election. The greatest increases are expected to be in the Pacific and Mountain regions, led by Las Vegas (6.2% growth over the next five years) and San Diego (6.1%). Los Angeles (5.7%), Phoenix (5.6%) and San Francisco (5.6%) round out the top 5.

The Great Lakes and Central South regions rank lowest in both radio and TV revenue projections. Slow retail growth and auto industry layoffs are cited as the main factors for the sluggish outlook in the Great Lakes region, where TV revenue is expected to grow 2.7%. The Central South, which includes the Mississippi markets still recovering from Hurricane Katrina, has projected TV revenue growth of 2.8%.