International Business Machines Corp. is encouraging software developers to build applications on its artificial-intelligence system Watson, looking to data analytics to help reverse falling revenue.

IBM will host a mobile developer challenge that urges programmers to create consumer and business apps powered by Watson, Chief Executive Officer Ginni Rometty said in a speech Wednesday at the Mobile World Congress in Barcelona. In three months, the company will choose three prototypes to receive design consulting and support to develop commercial apps.

IBM has been increasing its investment in Watson as the Armonk, New York-based company works to show clients the value of the technology, which analyzes troves of data and can answer questions in conversational language. The company said in January that it will spend $1 billion to create a new division around Watson to help spur growth after seven consecutive quarters of declining revenue.

“You run a business today and you reinvent it for the future at the same time,” Rometty said. “You go through these transitions. If you try to compare today to the past, today the speed is much faster.”

As sluggish demand for computer hardware has hurt sales, IBM has focused on more profitable, faster-growing areas such as data analytics and cloud computing, and the company has also sold hardware businesses.

Watson and other big-data services were the company’s primary focus in 2013, Rometty said in March. Last year, IBM boosted its expected sales from the data-analysis business to $20 billion in 2015, compared with an earlier forecast of $16 billion.

IBM acquired SoftLayer Technologies Inc. for $2 billion last year to increase its offerings in cloud services, where information is delivered online instead of stored on local servers. The company is spending more than $1 billion in the next two years to bolster SoftLayer’s platform, including integrating its Power Systems servers to help support the Watson technology.

The three winners of IBM’s challenge will be able to work with Watson developers to help them create marketable mobile applications. IBM will start charging developers after applications that use the tool become publicly available, Stephen Gold, vice president of IBM Watson Group, said in an interview.

“We all want them to be very successful,” he said. “We only win if they win.”