The chief executives of General Motors Corp and Chrysler LLC told Congress on Wednesday that slashing dealer networks were crucial for saving their companies.

We have no choice. We're all being called to sacrifice in order to build a stronger more viable GM, the company's chief executive, Fritz Henderson, said in testimony prepared for a Senate Commerce Committee hearing.

Jim Press, Chrysler's president, told lawmakers that a quick turnaround of its dealer network was crucial for its successful transition into an alliance with Italy's Fiat.

GM, which filed for bankruptcy protection earlier this week, plans to cut nearly 1,600 dealerships over the next 18 months. Chrysler wants to reduce its network by 789 showrooms by June 9, and is close to wrapping up its bankruptcy case.

(Reporting by John Crawley; Editing by Andrea Ricci)