Image copyright Getty Images Image caption Investors are anxious to see what Yahoo will do now that it has spun off its stake in Alibaba

Internet search giant Yahoo has reported worse-than-expected profits for the first three months of this year, adding to investor concern.

The company said it earned $21m (£14m) in the first quarter, compared with $312m a year earlier.

Although revenue from the company's mobile offerings increased by 61%, overall revenue from operations was $1.04bn, below expectations.

Shares in the firm fell nearly 2% in trading after markets closed.

"Yahoo is amidst a multi-year transformation to return an iconic company to greatness," said chief executive Marissa Mayer in a statement accompanying the earnings.

Investors are concerned about how the company will continue to generate revenue once it spins off its 15% stake in Chinese e-commerce giant Alibaba.

Ms Mayer highlighted a re-negotiated contract with Microsoft as a potential area of new growth.

She also said the company's partnership with search engine Mozilla had led to increased search traffic.