Google is expected to launch an online spreadsheet that will offer users a free alternative to Microsoft's Excel application. 

The search firm will allow a limited number of users to sign up for a beta of Google Spreadsheets from 9am Eastern Time today at the Google Labs section of its website. 

Google Spreadsheets will focus on collaboration and online access, allowing users to access the data from different computer systems rather than having to email files back and forth.

The service supports Microsoft Excel documents as well as the CSV format, and is based on technology from a company called 2Web Technologies that Google acquired last year, a company spokesperson told vnunet.com. 

Google Spreadsheets will lack some of the functionalities found in client-based applications such as Excel or the Calc application that ships as part of OpenOffice. Users will not be able to create charts, for instance, or right click.

The launch marks a second step by Google into the productivity software market following its acquisition of Writely in March.

The Writely word processor is currently in beta and the company is not currently accepting any new registrations. 

Google's agressive foray into the productivity software space increases the pressure on Microsoft as it prepares to launch a new version of Office in January.