NEW YORK (Reuters) - Microsoft is testing a new version of its online search service internally under the name of Kumo.com, a spokesman for the software company said on Monday.

The service is not yet available outside the company, but may eventually form part of Microsoft's attempt to catch up with Internet search leaders Google Inc and Yahoo Inc.

The new service was unveiled in an internal memo sent by the head of research at the company's online services division on Monday. It did not provide details about the new features.

"Kumo.com exists only inside the corporate network, and in order to get enough feedback we will be redirecting internal live.com traffic over to the test site in the coming days," said the memo from Satya Nadella. "Kumo is the codename we have chosen for the internal test."

The memo was first made public on The Wall Street Journal's All Things Digital blog.

Microsoft's Nadella reckons the company can put together a better search engine than those currently available.

"We believe we can provide a better and more useful search experience that helps you not just search but accomplish tasks," Nadella said in the memo. "An explorer pane on the left side of results pages will give you access to tools that help you with your tasks."

The Redmond, Washington-based company is struggling to catch up with runaway internet search leader Google, which is beginning to encroach on Microsoft's core software business.

Last year, Microsoft made an unsuccessful attempt to buy Yahoo for $47.5 billion. Executives at both companies have left open the possibility of a deal or partnership involving only Yahoo's search business.

(Reporting by Bill Rigby; Editing by Carol Bishopric and Anshuman Daga)