When Glencore issued a convertible bond in December 2009, the world’s largest commodities trader said the $2.2bn issue had been taken up by some of the industry’s blue-chip names. But several investors never went public.

I am now told that Fidelity and Capital Group, the two US-based fund managers, bought into the issue, which valued Glencore at $35bn.

At the time of the announcement of the convertible bond, Glencore disclosed only the names of some investors: First Reserve, the US-based private equity group that focuses on natural resources; GIC, Singapore’s sovereign wealth fund; US-based fund manager BlackRock; and Zijin Mining Group, the Chinese miner.

Glencore, Fidelity and Capital Group declined to comment.

The presence of Capital Group on the convertible bond is important as Glencore walks towards a flotation in London and Hong Kong or a merger with London-listed miner Xstrata, in which the trader owns a 34.4 per cent stake, later this year.

The publicity-shy Los Angeles-based fund manager is, through several funds, one of the top shareholders in Xstrata, so it could play a key role in any potential negotiation between Ivan Glasenberg, Glencore chief executive, and Mick Davis, Xstrata head.

Mr Glasenberg already counts another top Xstrata shareholder among its investors: BlackRock. Of course, having blue-chip fund managers such as Capital and Fidelity among the investors in the convertible bond does not guarantee any support for a merger move. But it does help. Their presence, kept under wraps until now, indicates that they are far more familiar with Glencore’s value than previously thought.

The market is abuzz with talk about Glencore’s initial public offering. Few talk about the merger. But savvy bankers maintain that the combination of Xstrata and Glencore remains firmly on the table. I wrote back in July that “Mr Glasenberg is likely to pursue the merger option to the bitter end. If that fails, he is determined to proceed with a multibillion dollar IPO”. I strongly believe the situation remains the same.

Within trading circles in Switzerland, it is clear what Glencore would prefer.

Executives joke that Xstrata’s name – a consultancy’s invention combining “extraction” and “strata” – actually stands for Glencore’s “exit strategy”. With Capital Group and Fidelity among the convertible bondholders, on top of the already disclosed presence of BlackRock, the “exit strategy” looks much easier.