DETROIT, JULY 31 -- Roger B. Smith, on his last day as General Motors Corp.'s chairman, said today that technology and value will be the cornerstone of the automaker's drive to reclaim a larger share of the vehicle market.

Smith, who will keep a seat on GM's board, said raising market share is the top priority for GM's new management team and Robert C. Stempel, who takes over as GM's new head Wednesday.

''I want to see us continue to raise our market penetration profitably, and I underscore the word 'profitably,' '' Smith said in an interview.

But many critics point to GM's declining share as the ultimate assessment of Smith's failed leadership. Beset by quality woes, look-alike cars and relentless competition, GM saw its slice of the U.S. car and truck market fall from 44.5 percent in 1980 to 35.8 percent now.

Smith, named chairman of what is now the world's largest industrial concern in January 1981 after joining GM in 1949, said that ''technolo and -- believe it or not -- value'' will be the keys to GM regaining share.

Smith also said more automation and flexible manufacturing techniques will help GM meet its promise of fully utilizing all North American vehicle assembly plants by 1992.

''That's part of the thing both Bob {Stempel} and the new team are working on,'' Smith said. ''There are a lot of things ... like the Impact {GM's planned electric vehicle}. New technical developments will add content to our cars.''

During Smith's reign, GM underwent a massive reorganization and a dramatic shrinking that closed more than a dozen assembly plants and idled tens of thousands of workers.

While supporters said Smith displayed vision by forging joint ventures with Toyota Motor Co., modernizing factories and creating Saturn Corp., his detractors said he spent billions to get GM into the electronics and defense businesses while ignoring a steady erosion in vehicle sales, notably in its traditionally strong mid-size car segment.

But Smith pointed to GM's restored profitability. ''When we took over, there was a $765 million loss,'' he said. ''We're now the number one company in the world.'' GM last year posted worldwide profits of $4.3 billion.

Smith chastised the media for what he called ''a lot of surface reporting.''