Top mobile phone maker Nokia on Wednesday bolstered its smartphone line-up to better battle Apple and announced a new location-based service with social networking site Facebook.

The announcements at the Nokia World event in Stuttgart are the latest riposte from the Finnish firm, which has lagged Apple's innovativeness as the focus of cellphone businesses shifts to services and software.

Nokia has been looking for business opportunities in offering services like music downloads or games to cellphone users as the handset market mature, but so far its offerings have had limited traction.

Nokia on Wednesday unveiled its X6 and X3 music phones, which will go on sale in the fourth quarter, priced at 450 euros ($641) and 115 euros, respectively. The X6 can play 35 hours of music and has 32 gigabytes of internal memory.

The company also unveiled a new version of its N97 smartphone, which will be priced at 450 euros, and said it was on the verge of going over 2 million units in sales of the original N97.

Nokia said its new top-end N900 phone will sell for 500 euros. The phone, which has computer-like functions, is the Finnish firm's first phone to use Linux software. The unveiling of the phone last Thursday helped to lift its shares 11 percent for the week.

Nokia said its new Booklet 3G, which marks its entry into netbook computers, will go on sale for about 575 euros and run on Microsoft's Windows 7 operating system.

With the move to making laptops, Nokia is crossing the border between two converging industries in the opposite direction to Apple, which entered the phone industry in 2007 with the iPhone.

TOUGH INDUSTRY

Nokia has seen its profit margins drop over the last few quarters as handset demand has slumped, and analysts have worried that entering the PC industry, where margins are traditionally razor-thin, could hurt Nokia's profits further.

However, Gartner analyst Carolina Milanesio said that Nokia had no choice.

Nokia had to do it. You see more and more PC guys getting into the mobile operators' shelves. Its kind of the counterattack, its not just defensive, said Gartner analyst Carolina Milanesi.

Nokia also announced a deal with Facebook that will allow people to update their location and status directly to the social networking site via a Nokia Ovi account.

The first phone to support the service will be the N97 mini, which will start shipping to retailers in October.

This deal sees Nokia catching up with rivals such as Apple and RIM. The big win is getting the Ovi brand and its Maps service featured on Facebook, said Paolo Pescatore, an analyst at CCS Insight.

Nokia shares were slightly down in the wake of the announcements, having fallen 0.7 percent at 9.35 euros at 0954 GMT but outpacing a 1.6 percent weaker Dow Jones Stoxx Technology index.

(1=.7023 Euro)

(Additional reporting by Brett Young in Helsinki; editing by Karen Foster)