The two companies plan to hold the morning news conference at the Computer History Museum in Mountain View, Calif., which is the city where Google is based.
Sun, headquartered in Santa Clara, Calif., has a productivity suite called StarOffice, which is based on the open source suite OpenOffice. StarOffice supports Microsoft's file formats and includes many of the core applications of the Microsoft suite, including word processing, spreadsheet and presentation software.
Google, on the other hand, has GMail, a Web mail application that lacks many of the capabilities found in Microsoft's more advanced Outlook desktop software.
Industry analysts speculate that the two companies may announce a desktop application that combines StarOffice and GMail capabilities, which would be accessible over the Internet.