General Motors' Saturn brand, launched in the 1990 as an 'import fighter', plans to double the size of its model range by the end of 2006, adding a sporty roadster, mid-size car and larger sport utility vehicle.

Associated Press (AP) said GM and Saturn executives discussed some details of the enhanced portfolio on Monday at GM's proving grounds northwest of Detroit, where automotive journalists drove two high-performance versions of Saturn's Vue and Ion models.

AP noted that Saturn's current lineup consists of three models: the Vue SUV, the Ion compact sedan and coupe and the L300 mid-size car, which Saturn has decided to drop.

Later this year Saturn will introduce the Relay minivan, followed in 2006 by the two-seat roadster, the new mid-size car and the larger SUV, which company officials call the Vue's "Big Brother", the report said.

"We're going to be more effective against the import makes like Honda, Toyota and Volkswagen," John Smith, GM's group vice president for sales, service and marketing in North America, told Associated Press.

AP commented that the brand, once billed as "a different kind of company" making "a different kind of car," certainly could use a boost after US sales to the end of March were down 30.4% compared with the same period last year and overall volume in 2003 was down 3.2% from 2002.

According to AP, Saturn has introduced the more powerful, sportier Red Line series for the Vue and Ion models to appeal to performance-focused drivers.

AP noted that the brand was launched to compete with low-cost imports such as Toyota, Honda and Nissan and, initially, all cars were built in the small town of Spring Hill, Tennessee, and Saturn maintained its own, very distinct identity.

At dealerships, Saturn's no-haggle pricing was intended to eliminate what many buyers find as a stressful experience, the report added.

But, Associated Press added, in recent years, Saturn has adopted many of GM's common practices for design, production and labour -- a change that analysts reportedly say was inevitable as the brand seeks to cut costs and become more competitive.