The paragraph above the percentage figure tells the story. Cerberus will give up a partial stake in return for access to engineering work to make Chrysler more competitive in small cars:
The two companies said in a joint statement they would share technologies and vehicle platforms. Under the proposed alliance, Fiat would not invest cash in Chrysler but would provide access to its successful small-car platforms, as well as to its more environmentally friendly and fuel-efficient engines.
