Royal and SunAlliance's (R&SA) sale of its beleaguered US operation could have stalled due to regulatory issues.

According to reports in The Daily Telegraph, the sale is unlikely to go ahead this year because US attorney Linda Kaiser, who had been overseeing the potential deal with US business Arrowpoint, is no longer involved in negotiations.

Objections have been raised by General Motors as to whether her involvement in the hearing had been a conflict of interest. Kaiser had acted for R&SA before on other deals.

According to reports, it is unclear when a full hearing will take place or if a decision can be reached.

A R&SA spokesman said the insurer was "comfortable" with the situation and still believed the deal would go through during the 2006 financial year.