Mercedes-Benz outsold its German rival BMW's core brand in July for the first time since March after the world's biggest premium car manufacturer saw its registrations fall by 7.7 per cent.
But deliveries of BMW's Mini and Rolls-Royce brands kept BMW ahead overall of DaimlerChrysler's Mercedes Car Group, which takes in Smart minicars and Maybach luxury limousines.
BMW group sales slipped to 102,452 units last month, but it was still its second-best July ever and trailed only July 2005, when the then-new BMW 3 Series saloon sent sales rocketing.
Limited availability of the 3 Series coupe version before a new generation of that model arrives in September also weighed on sales, as did slumping deliveries of its ageing X5 and X3 offroaders, BMW said in a statement.
BMW brand global vehicle sales fell 7.7 per cent to 86,597 units in July, while Mini brand deliveries also retreated 7.7 per cent to 15,804 cars as capacity upgrades at the plant at Oxford restricted supply.
Rolls-Royce sales gained 13.3 per cent to 51 Phantoms.
In the first seven months, group deliveries rose 5.7 per cent to 800,931 units. Sales of the 3 Series were up by a quarter to over 290,000 cars, while top-of-the-line 7 Series sales gained 16.4 per cent and 5 Series sales rose 3.3 per cent. Bank Sal Oppenheim car analyst Michael Raab said the sales slowdown at BMW was set to continue for the next few months while customers await a facelifted X3 due out next month and new generations of the X5 and Mini scheduled for the end of the year.
"The picture should reverse back in favour of BMW early next year," he said.
But the arrival of the new Mercedes-Benz C-Class car next year would put renewed pressure on BMW, he added.
Outgoing BMW chief Helmut Panke said last week that group sales up to July would show a clear rise, although not to the same extent as the eight per cent gain in the first half as year-on-year comparisons became more difficult.