Silicon Valley outfits were running a strict agreement not to poach each others staff, and when one of them broke the agreement it was enforced at a high level.

According to a court case which has opened in the US, Apple's Steve Jobs directly asked former Google Chief Executive Eric Schmidt to stop trying to recruit a junior Apple engineer. The court heard that Jobs' involvement  put the junior Google employee on the streets.

The 2007 email from Jobs to Schmidt was disclosed on Friday in the course of civil litigation against Apple, Google and five other technology companies. The proposed class action, brought by five software engineers, accuses the companies of conspiring to keep employee compensation low by eliminating competition for skilled labor.

Schmidt was also an Apple board member at the time of the email and he forwarded it on to other recipients.

"Can you get this stopped and let me know why this is happening?" Schmidt wrote.

Google's staffing director responded that the employee who contacted the Apple engineer "will be terminated within the hour." He added: "Please extend my apologies as appropriate to Steve Jobs."