Income at Ctrip.com International Ltd., the largest Chinese online travel agency by market share, continued to fall in 2012.

The agency's operational profit was 655 million yuan ($105 million) last year, down 39 percent from 2011, while its net revenue was 4.2 billion yuan ($675 million), up 19 percent, according to the company's annual results released on February 1.

Ctrip.com's income has declined since the third quarter of 2011, although its net revenue has maintained double-digit growth.

The low income is due to stiffer competition among Chinese online travel agencies and Ctrip.com's growing expenses for sales and marketing in 2012.

The agency spent 984 million yuan ($158.03 million) on sales and marketing last year, an increase of 58 percent, as China's online travel agencies began a price war last summer.