Photo

BERLIN — Microsoft is adding to its smartphone collection.

On Thursday, the tech giant introduced three new devices, its first ones since the completion in April of its $7.5 billion deal for Nokia’s cellphone business and just a few months after announcing the layoffs of 18,000 workers, primarily at the Nokia division.

The models will retail from $259 to $390 without a contract with a carrier, according to Microsoft. In contrast, Apple’s most recent phone, the iPhone 5S, costs $649 on its website.

By offering cheaper smartphones, Microsoft is hoping that it can finally break out from its mediocre market share to offer an alternative to the dominant operating systems from Apple and Google.

‘‘We want to drive scale through affordable phones,’’ Chris Weber, corporate vice president of mobile device sales, said in an interview. ‘‘We’ve created a product for someone who doesn’t want to pay a premium from our competitors.’’

Microsoft’s push to attract cost-conscious consumers, however, is likely to face an uphill challenge.

Rivals, including many Chinese manufacturers that are expanding aggressively into Europe with mass-market handsets, also have targeted individuals who want to buy a high-tech phone but are not willing to pay high prices to get the latest premium gadgets from Samsung and Apple.

And unlike Microsoft, which recently dumped a model that ran on the Android operating system, its competitors all offer Android-based handsets that give consumers access to more smartphone applications that are available on Microsoft’s app store.

‘‘Microsoft is gaining traction among brands, marketers and the developer community, but it still needs to offer reach to become the third must-support platform,’’ said Thomas Husson, a mobile expert at the research company Forrester.

Microsoft’s efforts to take on the likes of Apple and Samsung have failed thus far to convince consumers that they should try the company’s handsets.

In the second quarter of 2014, for example, the company’s Windows Phone operating system represented less than 3 percent of the market, compared with an 85 percent market share for Google’s Android software, according to the technology research company IDC.

Analysts said they were skeptical that these latest devices, which still cost significantly more than some of their Android-based competitors, will finally give Microsoft’s mobile ambitions the credibility the company has long sought.

However, Mr. Weber of Microsoft said that he saw ‘‘little innovation coming from our competitors. There’s a big market to tap into with these phones.’’

As it prepared for a big consumer trade show starting here on Friday, Microsoft said that it would expand its Cortana personal assistant product from the United States to other English-speaking markets and to China.

The service is similar to a rival product offered by Google, allowing individuals to communicate directly with the phone to arrange meetings, check schedules and get restaurant recommendations.