Yahoo Inc and Nokia Oyj will team up to boost their mobile Internet offerings, seeking to regain market share lost to rivals like Apple Inc and Google Inc.

Starting in the second half of this year, Yahoo will host Nokia's Ovi e-mail on phones exclusively and Nokia in turn will provide maps and navigation for Yahoo.

At a news conference in New York on Monday, the companies highlighted the importance of expanding services for users in emerging markets, for whom the phone is increasingly the primary device for using the Web.

Nokia is the leading handset vendor in many emerging markets, but it has struggled to grow in North America. Nokia Chief Executive Olli-Pekka Kallasvuo said working more closely with Yahoo would help it compete in the US.

"Location, maps and navigation will get more mind-share, will get more attention in the US and many more users in the North American market," said Kallasvuo. "This is one step we're taking in making our position stronger in the US."

The role of mobile services and software has become much more important since Apple and Google entered the phone market, forcing traditional handset vendors like Nokia and Samsung to hurry to build up their offerings.

Nokia has splashed more than US$10 billion in just a few years to build a new business by offering Internet services ranging from music downloads to e-mail, but these have so far won few paying customers.

Similarly, Yahoo has far less market cachet than Google, whose Android mobile operating system is used by many cellphone vendors from Motorola Inc to HTC Corp.

"One could always say the partnering of losers doesn't make a winner," said Pierre Ferragu, analyst at Bernstein Research.

"It is often true, but for Nokia, the right future that could lead to an interesting investment case is more about stabilizing its existing position and being successful in the mobile platform game."

Yahoo CEO Carol Bartz said the company had not invested sufficiently in its maps offering and hoped the partnership with Nokia would help it leap forward.