Synaptics Inc. said Thursday that profit in its most recent quarter more than tripled as demand grew for its touch screens for mobile devices and it got a boost from a tax benefit.

The company's results and sales outlook topped Wall Street expectations. Shares rose 18 percent in aftermarket trading.

Net income in the fiscal third quarter came to $36.4 million, or $1.07 per share. In the January-March period in 2012, profit was $11.4 million, or 33 cents per share.

A big chunk of its profit increase came from a $15.8 million tax benefit. Stripping out that and other one-time items, earnings rose to 79 cents per share from 51 cents per share.

Revenue rose 24 percent, to $163.3 million from $131.7 million, on gains in both its mobile and personal computer businesses.

Analysts polled by FactSet were expecting the company to earn 57 cents per share on revenue of $144.6 million.

Revenue in its mobile business rose 57 percent, while revenue from PCs fell 10 percent. Nearly two-thirds of Synaptics' revenue came from the mobile division.

The Santa Clara, Calif. company forecast revenue between $190 million to $205 million for the current quarter, which ends in June. Analysts were anticipating revenue of $157.6 million.

Synaptics' stock fell $1.02 to close regular trading at $38.54. Shares rose 18 percent to $45.32 in after-hours trading. The stock has risen 18 percent in the past 12 months.