Mercedes-Benz keeps delivering double-digit sales growth, but its overhauled line-up of luxury cars has yet to move it past German rival Audi, reported Reuters.

Deliveries of Daimler's flagship passenger-car brand rose 10.4 percent in May to a record 134,031 vehicles, helped by 30 percent growth in China, the company said on Friday.

That compared with 152,000 deliveries, or 10.8 percent growth, at Volkswagen's Audi which has outsold Mercedes every month this year.

Having eclipsed Mercedes in 2011 as the world's No. 2 luxury carmaker behind BMW, Audi sold 72,516 more cars than its Stuttgart-based rival in the first five months. Last year, the gap was 114,000.

But launches in March of Mercedes's new C-Class saloon and the GLA offroader may pave the way for a second-half turnaround, analysts say. Other recent overhauls include the top-of-the-line S-Class and the E-Class, both launched about a year ago.

"Mercedes will surpass Audi after the summer, that's when their refreshed lineup will take off," said Hanover-based NordLB analyst Frank Schwope.

The world's No. 3 premium automaker has a goal of pushing sales above 1.5 million this year, after 1.46 million in 2013.

By comparison, Audi is aiming to "clearly" exceed last year's record 1.58 million sales, while BMW is planning for deliveries of 2 million or more, after selling a record 1.96 million in 2013.