IDG News Service — Microsoft and Hewlett-Packard have expanded their partnership to develop and sell a common platform for delivering voice, video and messaging services to office workers.

The companies plan to spend US$180 million over the next four years on developing products and services for unified communications, and on sales and marketing for those products, said Meg Shea-Chiles, worldwide director for HP's partnership efforts with Microsoft.

The work will include development around HP's ProCurve networking products and Microsoft's Office Communications Server, Office SharePoint Server and Exchange products. HP will also certify its TouchSmart Business PCs and some smartphones for Microsoft's communications software, as well as some new IP desk phones that HP plans to develop.

Unified communications lets workers do things such as listen to a voicemail from within an e-mail program and make calls from an IM client. It includes presence software to show when people are online and what communications systems they have access to at that moment, as well as software that aims to simplify management on the back end.

Vendors such as Microsoft and Cisco are pushing unified communications as a way to make office workers more productive while keeping costs down. Many have latched onto the recession as a good time to promote these products, especially when companies are cutting back on travel and in-person meetings.

Microsoft and HP have an existing unified communications partnership that goes back several years. In 2006 they said they would deliver unified communications systems using Microsoft software and HP's blade servers, storage gear and professional services.

HP also partners with Cisco for unified communications. Its ProCurve gear has made the two companies compete more directly, but Shea-Chiles said HP's Cisco partnership continues unchanged.

She wouldn't say how many joint unified communications customers Microsoft and HP have today, but she said the investment they plan to make is "significantly" more than it has been. She also wouldn't say how much of the money they plan to invest is for product development and how much for sales and marketing.

The joint work will also involve adding greater support for Microsoft's Office Communications Server in HP's Business Technology Optimization software, including the ability to provide real-time quality-of-service metrics for IP-based voice and video traffic. OCS users will also be able to join telepresence meetings conducted with HP's Halo system.

The companies planned to make the announcement Tuesday morning at the Interop show in Las Vegas.

Forrester forecast in February that the market for unified communications products and services in North America, Europe and Asia would reach $14.5 billion in 2015, increasing by 36 percent each year during that period. But it also said the "long awaited takeoff" hinges on more interoperability with business applications.