Infiniti reported its first quarter sales climbed 18 percent on-year to 67,367 vehicles globally, with around 28,000 of those in March alone, the luxury car maker told CNBC on Thursday.

Sales in the U.S. rose 33 percent in the first quarter to a record-high 43,561 vehicles.

Roland Krueger, president of Infiniti Motor, attributed the increase in part to new models, including the Q30 crossover and Q60 sports coupe.

The car maker, which falls under the Nissan Motor umbrella, will also be launching a full-size SUV later this month.

"It confirms our product policy and our product expansion," Krueger told CNBC in Singapore on Thursday.

The increase in Infiniti's sales came as other car companies announced disappointing U.S. sales in March.

"The luxury segment usually always has a different growth pattern than the broader market. It comes down to the customer prerequisites that we are tapping into with our cars," he said. "In the premium segment, usually you find that developments are much more stable than they are in the mass-market. "

To be sure, in the U.S. in March, both luxury and mass-market car makers felt a pinch.

Ford reported that sales of cars fell 24.2 percent on-year in March, with SUV sales down over 3 percent.

Italian-American conglomerate Fiat Chrysler sold 5 percent fewer vehicles in March than last year, with a 33 percent decline in Chrysler sales. Fiat, the other half of the name, saw a 5 percent drop.

Jeep, typically Fiat Chrysler's most profitable and valuable division, reported sales that dropped 11 percent despite strong market favorability toward SUVs, which make up the entire Jeep lineup.

Toyota U.S. sales fell 2.1 percent in March. While Toyota's SUV sales supported overall sales, luxury brand Lexus posted a 7.5 percent drop.

Honda sales for March fell 0.7 percent, weighed by underperforming luxury division Acura.

Declining overall U.S. auto sales have come as loan delinquency rates have been rising.

In a note on Wednesday, Goldman Sachs noted that U.S. non-prime auto lending saw more than $110 billion in originations in 2016, for borrowers with credit scores below 620, the usual demarcation for subprime.

It attributed much of the increase in auto loan delinquency to weaker underwriting standards and lending standards. But Goldman added that the higher default rates were being priced in by much higher borrowing rates in newer deals, with some 2017 deep subprime auto asset-backed securities having average borrower interest rates above 19 percent.

Higher borrowing rates can easily price the subprime buyer out of the auto market.

—Mark Hogan contributed to this article.

—By CNBC.Com's Leslie Shaffer; Follow her on Twitter @LeslieShaffer1

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