New-vehicle sales, including medium- and heavy-duty trucks, surged in some key South American countries in 2011, based on the five major markets that have reported full-year results.

They include Argentina, Brazil, Chile, Uruguay and Venezuela. Four of these saw year-over-year increases, and each enjoyed the best volume year on record.

Argentina posted the biggest spike, with sales surging 26.5% to 883,350 units. Uruguay and Chile recorded double-digit gains of 20.3% and 17.4%, respectively.

New-vehicle deliveries in Brazil, the region’s largest market, grew 3.4% to 3.63 million units in 2011, compared with prior year. Despite the smaller increase, the result not only marked a record high for auto makers there, it also was the eighth consecutive annual increase since 1.38 million sales in 2003.

Venezuela was the only country among the five to suffer a loss, down 3.6% year-over-year, for a fourth consecutive annual decline. Sales totaled 120,689 units, compared with 125,202 in 2010, and well below the peak of 491,899 in 2007.

Brazil’s growth was somewhat curtailed by declines in each of the final three months, after 14 consecutive increases over the prior 15 months. The most impressive gains were made by auto makers with small market shares.

In comparison, the perennial top four by volume – Fiat, Volkswagen, General Motors and Ford – saw their combined sales fall 2.0% in 2011 from year-ago, while market share dropped to 66.9% from 70.5%. Only Volkswagen was able to eke out a 0.1% uptick, although its share slipped to 19.2% from 19.8% year-ago.

Fiat, the market-leader, saw deliveries dip 0.8% last year, while its share fell to 20.8% from 21.6%. GM’s sales dropped 3.9%, with share declining 17.4% from 18.7%. Ford was down 5.4%, with its share falling to 9.5% from prior-year’s 10.4%.

Total vehicle sales for the rest of the Brazilian industry climbed 16.3% in 2011.

The largest percentage gains among that group primarily came from Chinese brands, although each of the nine Chinese auto makers selling vehicles in Brazil held less than 1% of the market.

As a whole, China-based manufacturers saw a large increase on small volumes, with combined vehicle deliveries up 303% from prior-year. Their combined share rose to 1.9% from 0.5% in 2010 and 0.1% in 2009.

Jianghuai Auto, which reported sales for the first time in 2011, was the leading Chinese auto maker in Brazil with 23,747 units.

Other major gainers in 2011 in Brazil included the Renault-Nissan alliance partners, up 25.6% and 87.7%, respectively. Korean auto maker Kia saw a 41.8% surge in sales, with market penetration rising to 2.1% from 1.5% in 2010.

Several luxury brands, including Volvo, Porsche, Audi, Jaguar, Land Rover and BMW, also booked strong year-over-year increases in Brazil.