Glencore extended the long stop date for the merger to April 16, noting outstanding regulatory approval in China needed completion of an Xstrata court process.
Glencore's attributable profit for 2012 was down 75% year-on-year to $1 billion, while Xstrata profits fell 79% over the year to $1.2 billion.
Both companies cited slowed global growth rate and lower commodity prices as major influencing factors during the year.
Xstrata's revenue was down 7% to $31.6 billion while Glencore improved revenue 15% to $214 billion on the year.
Glencore flagged an improved performance by its metals and minerals division with generally good volume growth in copper and nickel.
Its adjusted earnings declined by 33% to $2.3 billion, however, due to weaker average commodity prices including nickel, zinc and copper down 23%, 11% and 10% on the year, respectively.
Glencore chief executive Ivan Glasenberg said the company saw 2012 as a turning point in the history of the mining industry.
"It has been evident for some time that capital discipline in the sector had been eroded by the period of higher commodity prices," he said.
"The result has been a material misallocation of capital across the sector in respect of organic capex and acquisitions.
"This provides a natural hedge in times of economic uncertainty as well as enabling the group to be at the forefront of spotting emerging trends and opportunities."
The company recorded a 9% increase in revenue from metals and minerals to $56.7 billion noting increased demand from China for copper and zinc.
Glencore's copper metal and concentrate sales increased 21% on the year to 2.3 million tonnes, but copper revenue fell 17% to $3.5 billion.
Xstrata, meanwhile, highlighted a "transformational" year with ten major projects commissioned in 2012.
The company flagged first production form its Ernest Henry underground copper mine and Lady Loretta zinc mine in Queensland and commissioning of its Lomas II copper project in Chile during the year.
It said lower copper volumes and ongoing costs helped reduce adjusted operating earnings 30% over the year to $8.1 billion.
The company's copper revenue was down 11% compared to last year to $13.4 billion.
Glencore and Xstrata closed 5.7% and 6.8% up overnight to $US391.20 and $1174, respectively.