U.S. light-vehicle sales totaled 1,049,220 in June – a slim 2.8% increase in daily sales that dropped the seasonally adjusted annual rate to a 12-month low of 11.4 million units.

Analysts had looked for June sales to equal or better May’s 11.8 million unit SAAR.

Unlike May’s dip below trend, largely attributable to Japan-based auto makers’ inventory shortages, June’s results suggest an industry-wide slowdown.

Daily sales for June – calculated over 26 selling days, one more than year-ago – were down 8.5% from May, which had 24 selling days. The decline was the largest single-month DSR drop since January, and the biggest May-to-June shortfall since 2007.

June deliveries brought U.S. LV sales for first-half 2011 to 6,310,655, 12.7% higher than like-2010.

General Motors underperformed the market as a whole in June, delivering 215,335 cars and light trucks – a 6.3% increase over year-ago DSR, but 10.1% less than May – accounting for 20.5% of total U.S. LV sales, compared with 20.9% the prior month.

While Ford and Chrysler finished closer to previously forecast levels, sales shortfalls at other OEM’s ultimately raised the companies’ relative market shares. Ford sold 190,505 light vehicles, an 8.6% uptick vs. year ago that equated to an 18.2% share of the market, the company’s best performance in nearly six years.

Chrysler sales accounted for 11.4% of sales, its highest share since March 2009. The auto maker’s 119,501 LV sales were directly in line with expectations.

Collectively, the Detroit Three’s DSR was up 10.9% over year-ago, but down 7.6% from May.

Related document: U.S. Light Vehicle Sales – June 2011

Toyota sold 110,937 LVs in June, trailing year-ago’s DSR by 24.1%. While the auto maker suffered from record-low inventories in early June, it sold more vehicles on a volume basis than in May and actually lifted its market share to 10.6% from 10.2% the prior month.

Toyota also managed to hold back anticipated runs from Hyundai and Kia. Combined, the Korea-based auto makers threatened in May and June to best Toyota for the first time but failed.

Hyundai sales jumped 11.2% over year-ago, while Kia’s soared 35.7%. Together, they claimed 9.9% of U.S. deliveries in June, compared with 10.2% in May.

The auto makers are struggling with their own inventory issues as they bump up against North American production capacity limits for some of their most popular vehicles.

While output rates began to return to normal at Toyota’s North America assembly plants in June, Honda sites still lagged levels recorded before an earthquake and tsunami stunted production in Japan.

Honda delivered 83,892 vehicles in the U.S. last month, a 24.3% decline in DSR, compared with year-ago, and a 14.7% plunge from prior-month. The auto maker accounted for just 8% of U.S. sales, its lowest share since July 2005.

While May and June produced disappointing results, it’s likely too soon to draw conclusions about the market’s overall direction. With incentive spending down across the industry, the pressure on consumers to buy now has decreased in the second quarter.

Against this backdrop, low inventories have made effective cross-shopping more difficult.

Though national average per-gallon gas prices have fallen from the $3.90 range seen during the spring, they remain some $0.80 higher than year-ago’s $2.75, according to the American Automobile Assn.

In the face of such volatility, buyers may be opting to defer purchases until the market situation stabilizes.

jsousanis@wardsauto.com