DETROIT — Ford Motor Co. supplanted Toyota as leader of the pack in J.D. Power and Associates' annual initial quality rankings released yesterday, grabbing more individual awards than any other automaker for the first time since 1998, when it tied for the top spot.

Ford ranked highest in five of 19 segments in this year's survey. That's two better than in 1998 — the last time a U.S. automaker was on top — when Ford tied with Toyota and Honda.

The automaker earned segment awards for the Ford Mustang, Lincoln Mark LT, Lincoln MKZ, Mercury Milan and Mazda MX-5 Miata. Mazda is 33.4 percent owned by Ford.

Porsche again dominated the overall ranking of brands, averaging 91 problems per 100 vehicles, as it had last year. That compared with a 2007 industry average of 125 problems per 100 vehicles. Last year it was 124.

Toyota Motor Corp., which grabbed the top spot in 11 segments last year, captured only four this year — the 4Runner, Sequoia, Tacoma and Lexus RX350/RX400h.

Ford's Lincoln brand, which jumped from 12th to third in overall vehicle quality, averaged 100 problems per 100 vehicles. It was behind Porsche and To-yota's Lexus luxury brand, which averaged 94 problems per 100 vehicles.

"We saw dramatic improvement from Lincoln," said Neal Oddes, J.D. Power's director of product research and analysis. "It was a fantastic year for the Mercury Milan, with dramatic improvements in terms of defects."

Overall, he said, Ford's strength came from new launches such as the Edge, MKX and MKZ.

Ford spokeswoman Anne Marie Gattari said those launches "speak volumes about what we're doing right."

"What we saw today is the result of several years of adhering to our design and manufacturing processes with complete discipline," she said. "It took some time for the results to be evident."

Toyota had seen its list of quality leaders decrease in a study released Monday by Strategic Vision Inc., a San Diego-based market research company and consultant to automakers. Despite improving its overall quality, Toyota led in one category in that study — down from four in 2006. South Korean automaker Hyundai Motor Co. led in five categories, outperforming its Japanese, European and U.S. competitors. Last year, Hyundai had no winners.

Joe Ivers, J.D. Power's executive director of quality and customer satisfaction, said there's no clear explanation for Toyota's drop. But several vehicles brought its quality performance down this year, including the Corolla, Prius and Lexus models.

It is worth noting, he said, that Toyota executives have been speaking publicly about their concerns about maintaining its historically high quality during a time of rapid growth.

"We're not used to seeing their vehicles go backward from a quality standpoint, and several of them did," he said. "It's no big change, but when things go backward for Toyota, it's unusual."

Toyota spokesman Mike Michels said the company was pleased with its results, adding that Toyota was the second-ranked non-luxury brand and stayed in the top 10 overall. Lexus also maintained its second-place ranking overall.