Hitachi Construction Machinery Co., the world's biggest maker of giant excavators, said it expects to fully recover from Japan's worst earthquake as early as this week after the calamity halted factories and parts supplies.

Production at five plants in Ibaraki Prefecture will probably return to the prequake level of 100 percent capacity this week, Chief Executive Officer Michijiro Kikawa said in an interview at his Tokyo headquarters. Output in late April dipped to 60 percent of capacity, he said.

The March 11 earthquake and tsunami disrupted supply chains at companies from Toyota Motor Corp. to chip maker Renesas Electronics Corp. Restoring production will help Hitachi Construction Machinery benefit from rebuilding demand at home and speed expansion in Asian markets, especially China, which accounts for half of global sales of excavators.

"We still face uncertainties about procurement of some parts," Kikawa, 63, said on May 11. "But things are far better."

Hitachi Construction Machinery has an annual worldwide production capacity of 60,000 excavators, its best-selling product. The company may expand annual production in China to the same level in the latter half of this decade after doubling output to 30,000 units by March 31, 2013, Kikawa said.

Spending on factories and equipment will triple to ¥52.6 billion this fiscal year to expand in Asia, the company said last month.

China will be "the major battleground" for the construction machinery industry, Kikawa said. The nation surpassed Japan in 2007 as the biggest market for the excavator industry, according to Hitachi Construction Machinery data. The company had a 15 percent share of the Chinese market last fiscal year.