Google, which operates a popular Internet search engine, said it would unveil a new corporate search product on Monday to help companies locate documents within their own databases.

By expanding into the corporate search business, Mountain View, California-based Google joins a number of companies including Verity Inc, Ask Jeeves Inc and CMGI Inc's AltaVista that are also selling enterprise software.

What makes Google different is that it is selling search hardware and software, all contained in a slim device it calls the Google Search Appliance, which businesses can install behind their own corporate firewalls and program to scan whichever documents they wish.

Google said the Search Appliance was capable of scanning a host of documents from personnel records to corporate literature, engineers' computer code and even employee emails.

However, it said each individual companies would be able to determine the parameters of the in-house searches it conducts.

The move into this corporate search business comes at a time when many companies are struggling with how to locate all their internal documents.

It also offers privately held Google, whose investors include Kleiner Perkins Caufield & Byers and Sequoia Capital, the opportunity to develop a new revenue stream based on selling a product.

Google's core consumer search business is free and is funded largely by advertising.

"Companies have a lot of content behind the firewall and struggle with how to get access to all that content to make employees more productive," said Joan Braddi, vice president of search services at Google.

"This is an extension of our Internet site search business. Many of our Web site customers have been asking us, 'Can you give me Google in a box?"'

Google said it had already sold several of the Internet appliances and counted among its customers National Semiconductor Corp.

The product comes in two versions; one that sells for $20,000 and scales to search up to 150,000 documents and a more powerful version for $250,000, which Google says can scan "millions and millions" of documents.

As with its consumer search product, Google maintains it can offer a superior corporate search product by providing better relevance and listing the most important documents at the top of the search results.