However, Xstrata cautioned the new proposal was not a firm offer and raised concerns that instead of the earlier announced merger that Glencore was making a takeover bid for the company.
"The proposal lacks sufficient information on key elements," the independent directors said in statement.
"On receipt of a detailed proposal, the board will carefully consider its merits and in particular whether it would represent a takeover of Xstrata by Glencore."
Under the revised proposal, Xstrata said Glencore has offered 3.05 shares for each Xstrata share, up from the earlier offer of 2.8 shares.
The initial offer had been resisted by Qatar Holding, a major Xstrata shareholder.
Glencore also proposed that its chief executive, Ivan Glasenberg, would become CEO of the combined companies. The earlier plan was for Xstrata CEO Mick Davis to take that role in the combined company.
The Xstrata independent directors noted the offer was lower than what would be expected in a takeover and raised concerns about plans to replace Davis, what it called "a fundamental change to the governance structure which underpinned the agreed merger of equals."
Xstrata shares were up 61 pence at 1,040 pence on the London Stock Exchange, while Glencore shares were down 20.75 pence at 371.60 pence.
Xstrata, which has more than 70,000 employees in more than 20 countries, controls the former Falconbridge operations in Canada that it acquired in 2006 after a takeover battle that lasted nearly two years.
Xstrata Nickel, a Toronto-based subsidiary has about 1,000 employees in Sudbury, Ont., and 850 at its mine and concentrator in northern Quebec.
Glencore, the world's largest publicly traded supplier of raw materials such as oil, copper and wheat, had said earlier that it would rather walk away from its proposed merger than overpay.
Earlier Friday, Glencore adjourned a shareholder meeting that had been scheduled to approve the merger after its chairman reportedly told investors that there had been some developments overnight.
"Apologies for bringing you here ... a new development has happened very recently," Glencore chairman Simon Murray told shareholders in Switzerland.
Murray held a vote to adjourn the meeting and said a new date would be announced in due course but didn't provide details.
Glencore shareholders were due to vote on whether the company should go ahead with a merger that would create a mining juggernaut with a market capitalization of more than C$90 billion.
But the plans were facing collapse as several major shareholders were demanding better terms to the deal.
Glencore already holds a 34 per cent stake in Xstrata.
The combined company would be called Glencore Xstrata and would control a chain of businesses from mining to refining, storage and shipping of basic commodities like coal, copper and corn.
Glencore is also awaiting final approvals to acquire Canadian agribusiness giant Viterra Inc. for $6.1 billion.
— With files from The Associated Press