(Bloomberg) - Bayerische Motoren Werke AG (BMW) held the lead in global luxury-car sales for the ninth straight year even as Audi and Mercedes step up efforts to overtake their rival.

Sales at the namesake brand increased 7.5 percent to a record 1.66 million cars in 2013, fueled by demand for the 3-series sedan and X1 compact sport-utility vehicle, the Munich-based manufacturer said. Including Mini and Rolls-Royce, deliveries rose 6.4 percent to 1.96 million vehicles in 2013.

“The BMW group posted record sales once again in 2013 and is clearly the No. 1 in the premium segment,” BMW sales chief Ian Robertson said in a statement. “Despite the prevailing headwinds in many markets, we aim to increase sales and make 2014 another record year.”

BMW is increasing spending on new models to fend off Daimler AG (DAI)’s Mercedes-Benz and Volkswagen AG (VOW)’s Audi, which have both vowed to take the lead in the segment by the end of the decade. To keep its edge, BMW plans to introduce the i8 plug-in hybrid sports car.

At the North American International Auto Show in Detroit, BMW showcased the new 2-Series compact coupe to help regain the luxury-car sales lead in the U.S., which it lost to Mercedes last year. The 2-Series will replace the 1-Series in the U.S. in the first quarter.

Narrower Gap

Both Audi and Mercedes narrowed the gap to BMW last year. Audi cut its deficit to 79,600 cars in 2013 from 85,000 the previous year, while Mercedes trailed by 193,500 vehicles compared with 220,000 in 2012.

“BMW still has quite a large edge over the competition,” said Frank Schwope, an analyst with Nord LB in Hanover, Germany. “Mercedes and Audi won’t able to catch up so quickly, as BMW can keep pace with new models.”

Audi reported an 8.3 percent rise in global sales in 2013 to a record 1.58 million cars, driven by the revamped compact A3 model and the brand’s growing line-up of SUVs. Mercedes, which lost the lead in luxury-car sales to BMW in 2005, delivered 1.46 million cars last year, up 11 percent.

Demand for BMW’s 3-Series surged 23 percent to more than 500,000 vehicles. The world’s best-selling luxury car will face tougher competition when Mercedes rolls out an overhauled version of the C-Class starting in March.

Deliveries of BMW’s X1 rose 9.2 percent to 161,000 vehicles. Mercedes is introducing the GLA compact SUV next year to compete with the BMW crossover.

Mercedes Gains

Mercedes, the world’s third-largest maker of luxury autos, sliced into No. 2 Audi’s sales advantage last year as its compact cars won new buyers. The company plans to further narrow the gap this year and is forecast to overtake Audi in 2015, according to forecasts from IHS Automotive.

Audi is responding with the new A3 sedan in the U.S. and a revamped version of the TT coupe in 2014. Over the next five years, Audi plans to spend 22 billion euros ($30 billion) to expand its lineup to 60 models from 49 and add production capacity in China, Brazil and Mexico.

All three German luxury-car brands posted sales records last year as they tap into rising wealth in countries such as China, India and Russia and a rebound in spending in the U.S.

This year, the manufacturers are again expected to grow. BMW is forecast to retain its lead with sales of 1.77 million vehicles, beating Ingolstadt-based Audi’s 1.66 million and Stuttgart-based Mercedes’s 1.56 million, according to data from IHS Automotive.