Google has launched a fee-based customisable search service for business websites.

Custom Search Business Edition is built on Google's free Custom Search Engine, which allows users to search within a specified group of websites.

The new service enables visitors to search within a company's website, Google said. Businesses can customise the search page with their own logos and colours and can include pages that are not on their own sites.

"For a fee, the Business Edition enables customers to enjoy technical support (email and/or phone), customisation of search results using XML API, a tailored look and feel, optional Google branding - and no ads next to the search results," the company said on its official Google blog.

For sites of up to 5,000 pages, the Custom Search Business Edition costs $100 per year. The fee for websites that have as many as 50,000 pages is $500 per year.

The service provides an option for businesses that want to bring Google's search technology into their organisation without paying for more-expensive products.

The company already sells the Google Search Appliance, starting at $30,000 for 500,000 documents, which indexes material in file servers, content management systems, databases and other sources. It also offers the Mini Search Appliance, starting at $1,995 for 50,000 documents.