Google has opened a new partner program for companies to produce add-on services for its business products.

Google Enterprise Professional is intended to expand products such as its Google Search Appliance and Google Desktop Search, designed to index and retrieve information held on company networks.

Google offers a basic level of service and customer support for its enterprise products. But not consulting, integration services or customisation work, said Dave Girouard, general manager of Google's enterprise business unit - which is where the partners come in.

About a dozen partners have already been signed up, and Google expects it to exceed 100 over the coming year, Girouard said.

Google will evaluate possible partners, aware that subpar work from them will reflect bad on Google, Girouard said. "We have to be pretty careful about who we work with in this program because in the end people are going to look at Google in terms of whether the experience with our products is good or bad."

Partners pay $10,000 per year to be in the program, and that includes a developer version of the Google Search Appliance, support and training. Google will act as a link between enterprise clients interested in professional services and its partners, matching clients with partners with the appropriate skills.

So far all approved partners are in the US, but the programme will be launched in Europe very shortly, Girouard said.