July 2 (Reuters) - Top U.S. automakers reported slower

growth in new vehicle sales for the second quarter after a

software widely used by dealers in their daily operations

suffered a cyber attack in the last few days of June.

General Motors ( GM ) reported a 0.6% rise in new vehicle

sales, compared with a jump of 19% last year, and said some

sales would shift to the current quarter due to the attack on

CDK's Dealer Management Software.

Market research firm Cox Automotive estimates U.S.

new-vehicle sales volume in the second quarter likely grew 1% to

nearly 4.2 million units. New vehicle sales had surged about 16%

year-on-year in the corresponding period in 2023.

"The CDK cyber attack has thrown a monkey wrench into sales

during the second half of June, affecting what is arguably one

of the most lucrative and busiest times of the month and quarter

for dealerships," said Jessica Caldwell, head of insights at

Edmunds.

The CDK outage was the latest hiccup for automakers in the

United States, as more than 15,000 retail locations were relying

on the retail technology provider for their dealer management

software.

Hyundai said second-quarter U.S. sales rose by

nearly 2%, compared with a 14% jump last year.

Analysts, however, expect vehicle retailers and automakers

to recoup most of the lost sales in July.

Automakers have benefited from pent-up demand for SUVs,

pickup trucks and hybrid vehicles. Discounts on certain models

and incentives have also attracted price-conscious shoppers.

"New vehicle affordability concerns remain prevalent and

inventories are not expected to advance as strongly as they have

done over the past 12 months," said Chris Hopson, S&P Global

Mobility analyst.

Electric-vehicle leader Tesla reported a

smaller-than-expected 5% drop in vehicle deliveries in the

second quarter, after price cuts and incentives helped stimulate

demand.