Nokia, the world's biggest phone manufacturer by volume, is getting ready to unveil three smartphone handsets at its annual trade show in London next week, according to leaked details.

The Finnish group has seen worldwide smartphone sales collapse this year after ceding ground in the race to Apple and the Android community, and is pinning its hopes for a comeback on its decision announced in February to adopt Microsoft's Windows Phone operating system.

Its first Windows handsets, believed to be called the Nokia 800, the Ace and the Sabre, will go on show next Wednesday and are likely to be available in the shops in mid-November, in time for the Christmas market.

The Nokia 800, dubbed the SeaRay, will come in a pink, light blue or black casing according to press shots leaked this week. It will have a curved glass 3.7in screen, and an eight-megapixel camera. Its body is based on the Nokia N9 smartphone, which was released in a limited number of countries earlier this year, but not in the UK or United States.

The Sabre looks more like the iPhone, with a 3.5in screen surrounded by a white frame and a five-megapixel camera. According to Pocketnow.com, which published the first photos of the handset, it will retail at between £260 and £300 without a SIM card and unlocked.

The third handset, the Ace, appears to be designed for business users. It is the only new device with a keyboard, which is hidden behind a slide screen, and the casing is black with silver detailing. According to TechWith, it has an eight-megapixel camera.

Nokia chief executive Stephen Elop said on Thursday as the company announced its quarterly results that he was encouraged by its progress with Windows Phone and confirmed that "we look forward to bringing the experience to consumers in select countries later this quarter". A wider release is planned for 2012.

The current phones will use Mango, the codename for Windows Phone version 7.5, which Nokia was not able to influence. The manufacturer will have a say in the design of the next iteration, codenamed Apollo, which is expected to be released in 2012.

Competition for the attention of Christmas shoppers will be fierce. This week Motorola unveiled its latest Android operated handset, the Droid Razr, and Samsung showed off its Galaxy Nexus, which also runs on Android. They both compete with Apple's iPhone 4S, which has been on sale since Friday last week and shifted 4m units in its first three days.