Xstrata priced its issue at 870 pence per share, at the upper end of expectations, and said the offer had raised about STG840 million.
Investor appetite for Xstrata enabled the company to boost the amount of stock on offer by a third last week, with punters ordering seven times more stock than was available.
Xstrata shares had a strong first day's trading, closing at 983p, up 13% on the offer price. More than 51 million shares changed hands throughout the day.
Glencore originally planned an IPO of its coal business, Enex Resources, which would have been Australia's largest for several years. However, in February it announced it would sell the business to its partly owned affiliate Xstrata.
The transaction will be funded through a mix of shares, cash and debt. Glencore will own about 40% of Xstrata after the listing.
Xstrata is only the seventh mining company to trade on the LSE main board.
