Sony Corp. plans to make its mobile-device business profitable next year as it boosts shipments of smartphones, the head of the unit said Monday.

The maker of Xperia handsets and tablets plans to sell more than 34 million smartphones in the year beginning April 1, Kunimasa Suzuki, chief executive officer of the unit, told reporters in Tokyo, without giving a more specific figure. Sony said last month it’s targeting 34 million shipments for the current fiscal year.

Sony President Kazuo Hirai is focusing on mobile devices as a key product to help revive the Tokyo-based electronics maker, which is reeling from four straight annual losses amid slumping demand for televisions. Sony bought out its mobile-phone venture with Ericsson AB last year for ?1.05 billion ($1.4 billion) and is eliminating about 15 percent of the unit’s workforce to make it profitable.

The firm is rolling out a global marketing campaign for its Xperia Z smartphone in more than 20 countries, it said late last month. The water-resistant handset was among new products released at the Consumer Electronics Show in Las Vegas in January.

Sales of the model topped 160,000 units in Japan in the two weeks after it was introduced on Feb. 9, Sony said in a presentation Monday, citing a survey by NTT DoCoMo Inc., the nation’s largest wireless carrier. The model was Japan’s top-selling smartphone in the three weeks that started Feb. 4, Sony said, citing researcher Keitai Watch.

The company is also introducing a new water-resistant tablet, the Xperia Tablet Z. Sony began selling its first tablet in 2011.

The electronics maker aims to generate ¥1.8 trillion in annual sales of mobile devices such as smartphones, tablets and laptop computers by March 2015, Hirai said in April. The section making those devices had revenue of ¥904.8 billion during the nine months that ended Dec. 31, while posting an operating loss of 72.6 billion, Sony said.

Sony last month cut sales targets for TVs, compact digital cameras, personal computers, camcorders and portable game players for the year ending March 31, while maintaining its goal of boosting smartphone shipments 51 percent.

Worldwide smartphone sales jumped 36 percent to 219.4 million units in the fourth quarter, according to research firm IDC. Sony’s market share rose to 4.5 percent from 3.9 percent a year earlier, making it the fourth-biggest manufacturer, the researcher said. Samsung was No. 1 with 29 percent of the market, followed by Apple with about 22 percent.

Sony sold 8.7 million smartphones in the quarter that ended Dec. 31, it said in a Feb. 7 statement. That compares with 27.4 million units for Apple Inc.’s iPhone 5 and 15.4 million units for Samsung Electronics Co.’s Galaxy S3 sold during the period, acestimates by Boston-based Strategy Analytics last month show.

The company’s ambitions in smartphones may be stymied by competition from Nokia Oyj, BlackBerry, HTC Corp. and other phone makers that are also trying to break Apple and Samsung’s grip on the market.