Major U.S. oilfield services provider Halliburton said Wednesday its third-quarter net income fell 12 percent because of higher costs and lower drilling activities. The Houston-based company earned 602 million U.S. dollars in the third quarter, down from 683 million dollars in the same period a year ago. Revenue rose 9 percent to 7.11 billion U.S. dollars from 6.55 billion in the year-ago period. Wall Street analysts expected Halliburton to earn 67 cents a share on revenue of 7.14 billion. Halliburton said lower activity and higher costs in the U.S. land market bit into revenue from the second quarter\'s level of 7. 23 billion. The company is a major provider of hydraulic fracturing services that unlock oil and natural gas from underground shale deposits. That technology helped boost natural gas production in the U.S. by about 20 percent between 2007 and 2011, according to data from the Energy Department. But the boom in production leads to lower prices. Natural gas prices dropped 29 percent in the latest quarter compared with a year ago as U.S. supplies remained high. Halliburton said the natural gas rig count on land in North America dropped by 18 percent in the third quarter as companies reduced production. The company, which focuses more on North America than its counterparts, suffers more as customers pull back or turn their focus to drilling for oil. The company expects a tough fourth quarter ahead. Halliburton, the world\'s No. 2 oilfield services company, has operations in more than 70 countries.