Commodity trader Glencore prepared the ground for a solid performance in its market debut, pricing its record-breaking offering of up to $11 billion in the middle of its initial range.

Shares in the grey market opened more than three percent above the offer price of 530 pence in London on Thursday, indicating appetite for the shares after many investors were left out of initial allocations.

At 530 pence -- the exact midpoint of Glencore's original range, but just below the middle of narrower guidance issued earlier this week -- the world's largest diversified commodities trader will be worth 36.7 billion pounds ($59 billion).

Glencore has said there is strong demand for its stock and had enough buyers to cover its offer within hours of starting the sale process earlier this month.

Glencore's offer has seen substantial interest from investors around the world and was significantly oversubscribed throughout the price range providing Glencore with a high quality, diverse and geographically spread investor base, Glencore's Chief Executive Ivan Glasenberg said.

The final decision to price at 530 pence per share was in line with earlier market expectations, after fund managers said any price above 535 pence could see the shares drop in the immediate aftermath of the listing.

The deal is priced to go. It is no surprise that it is oversubscribed, I think partly because of the competition created with the large number of brokers, analyst John Meyer at Fairfax in London said.

I think it will have a good start in London and I think Glencore has a lot of positive attributes to show. There are some high risk areas of the business, but there are some clearly very good parts that underpin it.

Liberum, one of the banks advising Glencore, said in a morning note that the listing could mark the end of a mini sell-off in both the sector and broader commodities.

Some investors, however, have said demand is largely due to the relatively small amount of shares being sold, the presence of cornerstone investors and substantial sales to tracker funds who are forced to own all companies in the main index.

Glencore's market value will propel the commodities trader straight into London's FTSE-100 index of bluechip shares, making it only the third ever company to do so,

The share price range was too high, full stop, as far as we were concerned, said one UK equities manager, at a house running more than 200 billion pounds of assets.

Put another way, had this been a 500 million pounds company, it would have had no chance of achieving the rating it is floating on.

Unconditional trading begins on Tuesday in London and Wednesday in Hong Kong, where Glencore is also listing.

Glencore, which is also floating in Hong Kong, will be listing a 16.4 percent stake, assuming no overallotment and no conversion of its convertible bonds.

But with a 10 percent overallotment option likely to take the total size of Glencore's offering to $11 billion, it is set to be London's largest-ever listing, overtaking Russia's Rosneft, which raised $10.6 billion in 2006.

It is already the biggest ever on the so-called premium listing segment of the London bourse.

($1=.6188 Pound)

(Additional reporting by Julie Crust and Paul Hoskins; Editing by Alexander Smith)