Google buys solar-powered drone maker Titan Aerospace

Titan Aerospace manufactures drones that fly at high altitudes for long periods of time

Internet search giant Google has bought US high-altitude drone maker Titan Aerospace for an undisclosed sum.

Google said the acquisition was intended to help the firm's efforts to expand internet access.

Titan Aerospace, which is building two types of solar-powered drones that can fly for years, says it expects "initial commercial operations" by 2015.

The firm, which has about 20 employees, will continue to be based in Moriarty, New Mexico.

"It's still early days, but atmospheric satellites could help bring internet access to millions of people, and help solve other problems, including disaster relief and environmental damage like deforestation," Google said in a statement.

"It's why we're so excited to welcome Titan Aerospace to the Google family."

Google's purchase follows Facebook's announcement earlier this year that it had bought UK-based drone maker Ascenta for $20m (£12m).

The two firms are competing to be able to use cutting-edge technology, like drones and high-altitude balloons, to deliver internet to more of the world's population.