Porsche is the world's most profitable carmaker

The German firm said its sales for the first four months of its financial year increased to 2.36bn euros ($3.5bn; �1.7bn) from 2.05bn euros last year.

Sale volumes at the company, best known for its 911 model, rose 18% to 30,700.

A recent law change means Porsche is able to up its stake in Volkswagen from 31%. Porsche has yet to commit, but many expect a takeover bid next year.

Porsche's four wheel drive Cayenne model enjoyed the biggest increase in sales during the four months, rising 76% from a year earlier to 13,400 vehicles.

Sales of the 911 were up only 3% to 10,800 cars, while those of the cheaper Boxter convertible fell by 17% to 6,500 units.

Porsche now expects total sales for its current fiscal year to be around the same level as the last, when it sold 97,513 vehicles.

'Chess game'

Porsche has yet to publicly commit itself to launching a full takeover bid for its compatriot Volkswagen (VW).

Many analysts expecte Porsche to move for VW next year

However, Porsche chief executive Wendelin Wiedeking used a briefing to journalists to indicate that he was already seeing opposition from Germany's powerful IG Metall trade union, and its members on VW's works council.

Using a chess analogy, he accused them of "trying to take out at least a rook or a knight on our side".

The law change that enables Porsche to increase its stake in VW came on 23 October, when Europe's highest court ruled that German legislation protecting VW from takeovers was illegal.

Under the so-called "Volkswagen Law", any shareholder could not exercise more than 20% of voting rights, even if their stake in the firm was bigger.