Edmunds.com, which provides information on the U.S. auto market, said Toyota will overtake Ford by mid-2007 in sales volume.
Toyota now often outpaces DaimlerChrysler AG's Chrysler Group and for two months this year sold more vehicles than Ford, which has seen sales drop almost 8 percent in 2006. Toyota's U.S. sales, meanwhile, have increased nearly 13 percent over the same period.
Ford, which is struggling with mounting losses in North America, has said it is aiming to hold its overall share of the U.S. light vehicle market at between 14 percent to 15 percent, including fleet sales, from the current 17.7 percent as it restructures by shutting 16 plants and cutting more than 50,000 jobs.
Ford expects a sharp fall in share next year as it is trying to pull away from sales of vehicles to car rental companies that typically carry steep discounts in favor of more profitable showroom sales.
Ford has ended production of its Taurus sedan, a model that was sold almost exclusively to fleet buyers in its final months.
Overall, Edmunds.com expects light vehicle sales to be flat in 2007, with sales near expected 2006 levels of 16.5 million.
"Gas prices will be a leading factor in how consumers choose what vehicles they purchase in the coming year," said Jesse Toprak, executive director of industry analysis for Edmunds.com, in a statement.
The firm expects Toyota's new Tundra truck, which is expected to be in showrooms in February, to take a chunk of large truck market share from U.S. domestic automakers.
This is a very profitable segment, so any loss in market share will have a disproportionately large impact financially, according to Edmunds.com.