Just six months after it triumphed as the top-selling U.S.-market minivan, the Chrysler Town & Country lags not only its Dodge platform-mate, but competitors from Honda and Toyota, as well.

Town & Country deliveries plummeted 31.8% in June, compared with like-2010, leaving the nameplate with 46,208 sales year-to-date, according to Ward’s data.

That total ranks fourth behind the Dodge Grand Caravan’s 56,970, Toyota Sienna’s 54,945 and new-for-’11 Honda Odyssey’s 52,968.

The Town & Country’s poor showing flies in the face of last month’s upbeat verdict from the influential publication, Consumer Reports, not to mention Chrysler’s total 24.8% year-over-year sales gain in June.

The auto maker’s 119,860 total deliveries in the month was good enough to beat industry giant Toyota for the second consecutive month.

However, the Grand Caravan’s robust sales performance – up 20.2% in June and 14.1% year-to-date – reflects distinct demand for light trucks.

Buoyed by the Jeep brand’s 67.5% surge, Chrysler dealers delivered 88,201 light trucks, compared with 31,659 cars.

Accordingly, the auto maker’s truck sales soared 36.2%, while car deliveries were nearly flat.

Sales of the revamped Jeep Compass and Jeep Grand Cherokee skyrocketed last month by 263.7% and 196.2%, respectively, according to Ward’s data, which is adjusted for sales days.

There were 26 selling days last month, compared with prior-year’s 25.

GM recorded a similar car-vs.-light-truck split in June, a trend it attributed to more moderate gasoline prices.

Sales of the all-new Chrysler 300 and its Dodge Charger platform-mate plunged 27.2% and 18.5%, respectively, in the month.

Continuing demand for the Fiat 500 mitigated the softness of Chrysler’s car sales. The minicar recorded its strongest month yet with 1,803 deliveries.

Through June, total Chrysler sales were tracking 21.1% ahead of like-2010.