Mercedes is looking to boost its F1 staff numbers by 100 people, according to German newspaper Bild-Zeitung.
The report said the German marque's experiment at trying to succeed again with Brawn GP's modest head-count of 450 at the Brackley headquarters has failed.
Bild said all the other top teams, including Red Bull (525 people), Ferrari and McLaren (both 550) have significantly higher staff numbers.
The news that Mercedes has embarked on a major recruitment drive for its F1 team follows the visit to the Nurburgring last weekend of Daimler chairman Dieter Zetsche.
The potential of this car has been exhausted
And team boss Ross Brawn was quoted as saying: "The potential of this car has been exhausted."
Bild said Mercedes GP is advertising for 39 jobs, with several of those positions "to be filled twice or even three times".