Retail sales were flat for a fourth straight month.

The Commerce Department reported that retail spending, which fuels most of the domestic economy, was virtually unchanged in June as debt-weary consumers continued to shun expensive purchases. Sales edged up only 0.4% to a seasonally adjusted total of $125.1 billion. Sales have not varied more than one-half of 1% up or down since February. Sales were 4.5% above year-ago levels, but growth has slowed to almost nothing. Spending during the first six months of 1987 was down 0.1% from the last six months of 1986.