Pic: AP.

BEIJING (AP) — Baidu Inc., which operates China’s most popular search engine, says its quarterly profit edged down 0.4 percent due to heavy spending to promote new mobile services but revenue soared.

The Beijing-based company said Thursday it earned 2.8 billion yuan ($459.9 million) in the three months ending Dec. 30. Revenue rose 50.3 percent to 9.5 billion yuan ($1.6 billion).

The company said marketing and administrative costs surged 135.1 percent from a year earlier while research and development spending jumped 80.1 percent.

The results reflect the rapid evolution under way in the world’s most populous Internet market as companies scramble to keep up with consumers who are shifting to surfing the Web from smartphones and other wireless devices.