Commodities giant Glencore International PLC said Wednesday that its partial share float later this month could value the company at $61 billion, making it one of the biggest initial public offerings in recentyears.

The Swiss-based company aims to sell part of its shares for between 4.80-5.80 pounds ($8-$9.67) on the London Stock Exchange starting May 24, with a secondary floatation planned for Hong Kong a day later.

Glencore would raise about $10 billion from the initial public offering that will catapult it straight into the FTSE 100 on the first day of trading. Almost a third of the shares available will go to so-called cornerstone investors, the company said. "Today we are able to announce one of the largest cornerstone investor participations ever achieved for an IPO," chief executive Ivan Glasenberg said in a statement.

He said the company looked forward to welcoming new shareholders "as long-term partners in our growth." Glencore has been at pains to stress to investors that current shareholders, said to be some 500 senior employees, will be prevented from cashing in their sharesforseveral years.

Glencore reported sales of $145 billion in 2010. For many years the privately held company, founded in 1974, was considered the silent giant behind much of the world's trade in raw materials.