RHJ International is due to make an improved offer to General Motors for a controlling stake in Opel.

The Industrial holding company will put forward its plans either today or tomorrow, reports The Financial Times.

In May GM signed a memorandum of understanding with Magna International but RHJ believes it has a better chance of securing the deal following issues between the US carmaker and Canadian parts supplier.

RHJ says it needs less German Government guarantees to finance the deal than Magna - 3.8 billion Euros compared to 4.5 billion.