The growing popularity of Mercedes' smaller, lower-margin models and the revamped flagship S-Class saloon helped boost core brand deliveries by 14 percent last month to 162,746 vehicles, an all-time monthly record, parent Daimler said on Tuesday.

Mercedes-Benz also posted its best-ever quarterly sales between July and September of just over 412,000, up 12 percent from a year earlier. Daimler is due to report third-quarter financial results on Oct. 23.

The world's No. 3 premium automaker is rapidly improving its performance in China where sales surged more than 30 percent in the nine months through September to 203,485 models, with September alone up 24 percent.

That compares with 11 percent growth in 2013, the first year after Daimler had fixed competing sales channels in the world's biggest auto market and created a new management board position responsible for Chinese operations.

Analysts have said the launch in March of Mercedes's new C-Class saloon and the GLA offroader may pave the way for further improvement in the second half, while last year's overhauls of its S-Class and E-Class model should continue to do well.

Stuttgart-based Mercedes-Benz, which slipped behind Volkswagen's VOWG_p.DE Audi in 2011 in the global premium sales race, has a goal of pushing brand sales "clearly" above last year's record 1.46 million cars.

Nine-month sales were up 13 percent at a record 1.195 million, also powered by gains of 8.4 percent in the United States and 7.6 percent in Europe.

Sales of the two-seater Smart city-car plunged 21 percent in September to 6,770 units, as customers awaited a new generation of the tiny models, due to hit dealerships next month.

Mercedes' rivals Audi and BMW BMWG.DE, aiming to boost 2014 sales to over 1.7 million and 2 million or more respectively, are expected to publish September sales later this week.

Separately, sales growth at VW's mass-market passenger-car brand stalled for a second month in September, edging up only 0.2 percent as gains in Europe and China were offset by declines in the Americas and Russia.

(Reporting by Andreas Cremer; Editing by Arno Schuetze and Susan Fenton)