Ford is considering selling its controlling stake in Mazda after 30 years as an investor in the profitable Japanese car firm. The Blue Oval currently owns one third of Mazda, equating to shares worth $1.36 billion. The American car giant would use the capital raised from selling its stake to bolster its struggling operations back in the US. Both Mazda and Ford refused to clarify their positions today. A Ford spokesperson told Autocar: "We do not want to comment on speculation."However an unnamed Ford US insider revealed the ongoing deliberations, adding, "No decision has been reached, yet." The Dearborn source confirmed that discussions were underway but that a decision wasn’t imminent. All this has prompted speculation over who might buy the controlling stake in Mazda. Tata Motors today released an intriguing statement denying that it is interested in buying the shares. Whatever the outcome, there's no doubt that Ford could use the estimated $1.36bn cash injection. The American car market has slumped to its lowest level since 1991 amidst the global financial crisis. Ford has lost $23.9bn since 2005 as sales of its SUVs and pickups - which provided the bulk of North American profits in the 1990s – have slumped.However market experts suggest that selling Mazda isn't all about the money. Many argue that Mazda has no obvious role in Ford's future strategic plans. Ford of Europe and its small car line-up has already made Mazda redundant. And Alan Mulally, Ford's CEO, has made clear his intention to unite the Blue Oval's often disparate worldwide operations.