Glencore is likely to price its record initial public offering at or above 530p ($8.60), sources close to the matter said, valuing the world's largest commodities trader at a minimum of 36.5 billion pounds ($59 billion).
Investors with price limits below 530 pence are likely to miss out, one of the sources said on Tuesday.
Glencore, which will list in London and Hong Kong, narrowed its price guidance earlier this week to 520 to 550 pence, according to sources familiar with the deal, lifting the midpoint of the offer marginally to 535 pence from 530 pence.
Order books for shares in Glencore, London's largest listing to date, were fully covered within hours of the start of the sale process and were multiple times covered by the end of last week, despite volatility in commodity markets.
Part of that success, however, is a result of the relatively small stake in the company being placed with funds and because of Glencore's size and immediate entry into the FTSE bluechip index, which makes it a must-buy for many.
It said last week that it would close books on Tuesday, a day early and ahead of the official end of its roadshow, in an indication of appetite for the shares but also an illustration of the complexities of an offering stretching across the globe.
Books will close at 1500 GMT and the final price will be made public on May 19, when conditional trading begins.
Founded in 1974 by trading sensation Marc Rich, Glencore has until now held on to a fiercely prized tradition of discretion. Its publicity shy top executives, however, will become paper multi-millionaires with the initial public offering, with Chief Executive Ivan Glasenberg's own stake worth $10 billion.
Unconditional dealing in London will begin on May 24 and in Hong Kong on May 25.
(Reporting by Clara Ferreira-Marques; editing by Paul Hoskins)