US auto giant Ford's first-quarter profit plunged 39 percent on weaker sales in its key North America market amid severe winter weather. Net income was $989 million in the first three months of the year, down from $1.6 billion a year ago, the Ford Motor Company said Friday. Adjusted earnings of 25 cents per share came in six cents below Wall Street expectations. Revenue edged up to $35.9 billion. Ford, the second-largest US carmaker, said wholesale auto sales in North America fell two percent in volume and revenue declined five percent. North America pre-tax profit fell to $1.5 billion, down $892 million from the year-ago record profit. The decline was in part due to higher costs of $500 million linked to weather-related charges and vehicle recalls. Global auto sales volume rose six percent and revenue climbed one percent from the 2013 first quarter. Ford confirmed its 2014 full-year outlook for profit between $7 billion to $8 billion. The Dearborn, Michigan-based company plans to launch 23 new global vehicles this year. "We had a solid quarter, and we are on track with our most aggressive product launch schedule in our history," Ford president and chief executive Alan Mulally said in a statement. Ford shares tumbled 2.3 percent to $15.95 in pre-market trade on the New York Stock Exchange.