VANERSBORG, Sweden, June 17 (Reuters) - Creditors of Swedish carmaker Saab on Wednesday approved a writedown of 75 per cent of 10.6 billion crowns (US$1.4 billion) in debt, most of which is owed to its US parent General Motors.

The vote at the hearing paves the way for the court to approve the writedown, which it is expected to do later on Wednesday.

The ruling came after General Motors said on Tuesday it had struck a preliminary deal for sportscar maker Koenigsegg to take over the loss-making Swedish firm after two decades of US ownership.