Car parts like brakes that need to be replaced for safety reasons are doing well for Genuine Parts Co., but retail customers still aren't eager to buy parts they may not immediately need.

Still, the Atlanta parts distributor said it had seen a "marked improvement" in its retail auto parts sales in the first quarter of the year, even as the commercial auto parts business' growth remained higher.

The company has yet to see a significant impact from the falling price of gasoline over the last two weeks, Genuine Parts president Paul Donahue said in a company conference call Thursday, but he said he feels optimistic about the company's prospects for growth.

Where Genuine Parts is seeing the most growth is in its industrial parts group. Sales in the motion industries category grew 12 percent in the quarter and manufacturing increases have continued to aid both that and the electrical businesses, the company said.

The company's weakest business continues to be office products. Despite increased sales of cleaning and break room supplies, the category was dragged down by lower sales of office supplies, furniture and technology products.

Genuine Parts expects both the office supply and electrical sales to pick up through the year. In its first quarter, the company made $146.3 million, a 15.6 percent increase over its profits for the first quarter of 2011. Its total sales were up 7 percent compared to the first quarter of last year.