Kuwait's Investment Dar Co, Aston Martin's controlling shareholder, has approached potential buyers for the UK-based maker of luxury sports cars, Bloomberg has reported, citing five people with knowledge of the matter. The company, which owns 64% of Aston Martin, has hired Rothschild to advise on the sale, said one of the people. A sale has proven difficult because investors haven't been willing to match the price the Kuwaiti owner paid five years ago, said two of the people. Investment Dar has sought about $800m for its stake, one person said. Toyota Motor Corp hired an auditor to conduct a one-week study on buying a stake in Aston Martin, according to a person familiar with the matter. However, a representative at Investment Dar, who asked not to be named, denied the company is seeking to sell Aston Martin.