Update: General Motors originally planned to run its employee discount pricing though until today but the company is reportedly planning to extend the program for another four weeks due to its success. GM’s sales so far this year in the U.S. are down 18% on last year’s levels, while numbers for its pickups are down nearly 23% for July alone.

The information comes from people familiar with GM’s plans, who revealed to Bloomberg that sales were boosted significantly last month after the program was launched. The company also needs to clear out its current inventories in preparation for the arrival of its 2009 model fleet.

Original: General Motors will offer employee discounts to everyone for all its brands starting this Wednesday and is expected to run the promotion until September 2. The information was first revealed in a memo to Buick, Pontiac and GMC dealers, and it has since been confirmed by GM that the discount would be applied to all 2008 models, as well as the 2009 Pontiac Vibe.

On some models, customers will be able to receive up to $6,000 in cash plus the employee discount.

The discount will vary depending on the vehicle line, but consumers can expect price cuts of several thousand dollars. For example, a 2008 Buick Enclave crossover (pictured) that lists for $44,010 will sell for an employee price of $39,561 and a Buick Lucerne sedan that lists for $35,220 will cost just $31,813 with the employee discount.