The Ford Fusion midsize sedan is on the cusp of achieving 1 million sales, a milestone it likely will hit sometime this month, Ward’s data shows.

Through June, Fusion deliveries stood at 988,182 units. With the popular model averaging 25,000 sales a month so far this year, the 1 million-unit bogey is not far off.

The Fusion saw 20,808 deliveries in June, a 15.9% jump compared with like-2010.

Launched in October 2005 as a ’06 model, the Fusion sold a modest 4,978 units in its first month. Since then, it has enjoyed a meteoric rise, shooting to the top of the Lower Middle car segment, as defined by Ward’s.

Indeed, the Fusion has been tops in its segment since 2008, with its share hovering at about 50% over the last several years. Other notable players in the segment include the Hyundai Sonata, Kia Optima and Chevrolet Malibu.

The Fusion’s best sales year was 2010, with 219,219 deliveries, according to Ward’s data.

In another milestone, Ford this month eclipsed the1 million-unit mark in overall light-vehicle sales for the year, with 1,052,957 deliveries through June.

Last year, the auto maker took until July to surpass 1 million LVs. Only General Motors has sold more than 1 million units already this year, hitting the target in May. Toyota is projected to deliver its 1 millionth LV in August.

Ford’s total sales in June rose 8.7%, compared with year-ago, to 190,505 units, based on 26 selling days vs. 25 in like-2010.

Deliveries may have been better had lawmakers in California, the largest U.S. vehicle market, not passed last-minute legislation changing registration fees 1% beginning in July, says George Pipas, Ford’s top U.S. sales analyst.

“So we, and other manufacturers as well, experienced some softness in California at the close (of the month),” he tells reporters and analysts in a conference call today.

Fullsize-pickup truck sales rebounded somewhat in June, largely due to lower gas prices, he says, with the F-Series up 1.1%, compared with year-ago, to 46,708 units. And for the second consecutive month, F-Series buyers bought more V-6-equipped trucks than those fitted with a V-8

Deliveries of Ford’s smaller cars also played a role in the June increase. Focus and Fiesta sales tallied 21,385 and 5,535, respectively. The result would have been higher if the auto maker had more vehicles in stock, Pipas claims.

Among the new Focus models, the high-end Titanium trim level is flying off lots 40% faster than lower-priced versions, says Ken Czubay, vice president-U.S. marketing, sales and service.

“Customers are bringing luxury trade-ins from Infiniti, Volvo and BMW,” he adds.

Czubay says through the first six months of 2011, Ford’s retail sales rose 19% in the Midwest, 25% in the Eastern U.S., 21% in the Southeast and 30% in the West.

Western sales were “dominated by California,” he says. “Retail sales (in California) were up 33% in the first six months and 36% in June (alone).”

Ford is approaching the year’s second half with “cautious optimism,” Czubay says, noting there may be pent-up demand partially due to vehicle shortages caused by the Japanese earthquake and tsunami in March.

However, fluctuating gas prices and a still-shaky U.S. economy are reasons for caution, he warns.

Ford ended June with 426,000 units of inventory, including 109,000 cars and 317,000 trucks, equating to a 57 days’ supply, a level with which Ford is comfortable, Pipas says.

bpope@wardsauto.com