Infiniti will delay the start of production of its upcoming QX55 by five months, the automaker told its supply chain.

The QX55 was to arrive in dealerships this summer as a coupe-like version of Infiniti's QX50 compact crossover, with production beginning in June. But it will now start in November, suppliers were informed in a letter dated Jan. 13 from Nissan North America's manufacturing team in Aguascalientes, Mexico.

The letter vaguely referred to a need "to ensure production capability" at the plant.

A U.S. spokesman for Infiniti did not elaborate on the situation, except to say, "As noted in the letter from the production facility to suppliers, operational efficiencies drive projects to move — sometimes forward, sometimes backward— as we progress toward the start of production of a new model."

The Infiniti QX55, like the QX50, will be assembled at the $1.4 billion joint-venture Aguascalientes plant co-owned by Nissan and Daimler.

A potential competitor to the Mercedes-Benz GLC Coupe and BMW X4, the new Infiniti model is expected to be powered by a 2.0-liter turbocharged four-cylinder engine.

The QX55 has a sloping roofline inspired by the first-generation FX performance crossover. While the new model shares design elements with the QX50, the fascia is different and sports a new grille design.

The QX55 is aimed at customers "for whom utility is still important, but styling is paramount," Infiniti Product Planning Director Tim Franklin told Automotive News in October.

"It's targeted at pre-family [couples] and singles who are willing to take some compromise on space for style," Franklin said.

Adding a coupe-like derivative is a low-investment way to bring new customers into the brand, said Ed Kim, an analyst with AutoPacific.

"It offers a more style-driven counterpart to the QX50 that can potentially bring more conquest customers to Infiniti," Kim said.

"As sales of Q50 and Q60 [cars] continue to shrink, Infiniti needs to backfill their lost volume with new and relevant products. QX50 is one step, and QX55 is yet another."

The QX50 also suffered launch snafus. While executives heralded the QX50 as the brand's most important product since the original Q45 luxury sedan three decades ago, the model so far has failed to gain market traction. U.S. sales of the crossover fell 27 percent last year.

The brand's management last year acknowledged that the QX50 had not been launched with the right configurations.