Coca-Cola has announced it will raise prices this summer. And some retailers are worried.

The Atlanta-based beverage giant says prices will spike 3 to 4 percent.

The company cites higher prices for corn, oil, aluminum, and plastic.

Coke says not all products will be more expensive, depending on the brand and packaging.

But retailers say that once Coke prices go up, Pepsi and other soda companies may soon follow suit.

Others say that a price increase will only deter customers who are already pinching pennies.

Coca-Cola expects the price jump to take effect by the end of July.

Tags: economy, Coca-Cola, retail, soft drinks, price increase, soda