The companies said on Friday they had received formal approval from the Ministry of Commerce of the People’s Republic of China.

The transaction received clearance from the United States Department of Justice in late May.

The acquisition is expected to close shortly, the two confirmed.

"Since we announced our plan to acquire Bucyrus last November, we have continued to hear from our customers that this complementary expansion of our mining product range is what they have been looking for from Caterpillar,” Caterpillar chairman and chief executive officer Doug Oberhelman said earlier this year.

“This will position us to better serve the increasingly complex requirements of those customers."

The acquisition positions Caterpillar to capitalize on the robust long-term outlook for commodities driven by the trend of rapid growth in emerging markets, Oberhelman said.

Caterpillar will fund the acquisition through a combination of cash from its balance sheet and debt. It does not plan to issue equity to help pay for the acquisition.

A significant motivation for the deal, Cat’s largest acquisition ever, was the estimated $400 million of annual synergies beginning in 2015 derived from combining the companies’ complementary product offerings and financial strength.

Eighty-five year old Caterpillar produces construction and mining equipment, diesel and natural gas engines, industrial gas turbines and diesel-electric locomotives.

In 2010 it recorded sales and revenues of $42.588 billion.

Bucyrus, which will take the Caterpillar name, designs and manufactures mining equipment for both the surface and underground sectors; its surface mining equipment is used in coal, copper, iron ore, oil sands and other minerals.