RHJ International will present General Motors with an improved offer for a controlling stake of Opel on Monday or Tuesday, according to two people familiar with its plans.

In May, GM signed a memorandum of understanding on the stake with Magna International, but RHJ now thinks it has improved chances of winning the deal as negotiations between the US carmaker and Canadian supplier, which is bidding with Russia’s Sberbank, have hit snags over intellectual property and other issues.