German luxury car maker Porsche's first-half profit has leapt fourfold owing to its stake in Volkswagen, but it said sales were down and it could not give a full-year forecast.
Porsche's net profit jumped to 5.5 billion euros ($10.7 billion) in the six months from August to January, mainly as a result of a spike in the value of VW shares in October, the company said.
Porsche owns 50% of VW, the biggest European car maker, and wants to raise that holding to 75%.
In its 2007/08 fiscal year, Porsche had reported a first half profit of 1.26 billion euros.
Pre-tax profit climbed to 7.34 billion euros from 1.66 billion euros, a result that also stemmed largely from transactions in cash-settled options on VW shares.
Cash-settled options are stock option contracts under which settlement is done via the payment of cash equal to the difference between the market value and the contractual value when the option is exercised or expires.
Porsche has used such VW-based instruments to make huge profits in the past two years.
Revenue from Porsche car sales fell meanwhile, by 9.2% on a 12-month basis, to 3.32 billion euros.
The company said that no reliable forecast for the near term was possible, with neither Porsche nor VW able to escape the effects of a sector-wide slump, although VW expected to do better than rivals.