* Titan has not been redesigned since it was introduced in 2003
* Titan's share of U.S. pickup truck market only 1.1 percent
* All of Titan's competitors are newer
DETROIT, Feb 6 (Reuters) - Nissan Motor Co's U.S. arm is preparing to expand its lineup of full-size pickup trucks as it replaces the aged Titan, which has not been significantly refreshed since it was introduced in 2003, the company said on Wednesday.
Engineers and designers are leaving "nothing off the table" in delivering a competitive truck to U.S. consumers, said Pierre Loing, Nissan North America chief for product planning and marketing strategy. He would not say when it would be introduced.
However, a source familiar with the company's thinking said the next-generation Titan is slated to debut in April 2014 as a 2015 model.
Loing said Nissan wants to regain a market share of between 5 percent to 7 percent of the U.S. full-size pickup truck market, which it had in Titan's early years. Nissan's share of that market last year was 1.1 percent.
The segment accounts for 1.7 million annual sales, said Loing, and is dominated by the three Detroit-based automakers, led by Ford Motor Co, followed by General Motors Co and Chrysler Group.
Titan sales were nearly 100,000 a year after it was introduced. But sales fell as the truck got older and its competitors issued new offerings with enhanced features.
Last year, Nissan sold 21,576 Titans in the U.S. market, down 2 percent from 2011.
The three U.S. full-size pickup truck manufacturers and Toyota Motor Corp all have much-fresher options for consumers and business buyers.
Pickup truck market leader Ford's F-series sold 645,316 units last year. Ford teased its next-generation model last month at the Detroit auto show. The new F-series, led by the F-150 pickup, goes on sale early next year as a 2014 model.
Chrysler Group's Ram Truck introduced a redesigned Ram 1500 pickup truck last fall for the 2013 model year.
Redesigned versions of the Chevrolet Silverado and the GMC Sierra from General Motors will be introduced in late spring as 2014 models.
Toyota is introducing a new version of its full-size pickup Tundra on Thursday at the Chicago auto show. It will be a 2014 model when it goes on sale later this year.
Nissan now makes four-door crew-cab and king-cab versions of the Titan, both of which are equipped with a V8 engine, said Loing. "There's a lot of space for us to increase our coverage" of the broader pickup market, he said in an interview.
Loing said Nissan may make a V6 version of the full-sized pickup truck.
Larry Dominique, president of automotive consulting firm ALG, said that while U.S. pickup truck owners are fiercely loyal to their brand, Nissan has an opportunity to convince younger truck buyers to try a Titan once the redesigned version is available. Dominique, who until 15 months ago headed Nissan's product development and led the team that created the original Titan, said he thinks Nissan will offer a two-door regular cab Titan in addition to the king cab and crew cab it has now.
Nissan would not say whether the Titan will remain on the same platform it shares with the Armada full-size SUV and the Frontier mid-size pickup truck.
Loing said that Nissan in recent years has made a priority of developing newer versions of its higher-selling sedans, including the Altima, Sentra and Versa, as well as the Rogue compact crossover, rather than redesign the Titan. As a result, it is one of the oldest designs in the full-size truck segment.
Dominique said another reason it has taken so long for Nissan to introduce a new pickup truck is that the company had been working with Chrysler to develop a truck based on the full-size Ram platform, but that effort died when Chrysler underwent the financial strains that led to its 2009 bankruptcy.