Search giant Google has launched a new hosted service designed to enable firms to place user-friendly, self-branded site search functionality on their web sites.

Google Site Search builds on the firm's Custom Search Engine service, adding the ability for site owners to customise the look and feel of the search interface to fit with the design of their site.

The service also allows firms to influence search results based on how old the documents are or to put specific sections of the site at the top of search results, according to Google's UK head of enterprise, Robert Whiteside.

The technology has also been designed to recognise synonyms in an attempt to improve the relevance of results by marrying users' search terms more closely to the language firms use to describe their products.

"Firms spent a lot of money attracting visitors to their web sites and 90 per cent of consumers choose search to find the information they're looking for to make a purchase," added Whiteside. "Having highly relevant search is very important."

He added that because the service is based on a cloud computing model, firms of all size, even those with minimal IT resources can take advantage of site search.

There is also email and phone support and the option to turn off ads, and integration with Google Analytics to give deeper insight into user behaviour, said Google.

The service costs $100 a year for searching up to 5,000 pages. Prices for larger volumes of pages are available here.