ChemChina, the company making China’s biggest takeover bid yet, is part of a phalanx of highly-leveraged corporations that are spearheading “China Inc’s” purchase of foreign assets and raising questions over the financial sustainability of acquisitions.

So high are the debt levels at ChemChina and several other companies behind some of the country’s biggest overseas investments that financing for the deals would have been difficult or prohibitively expensive were it not for the backing of the Chinese state, analysts said.

ChemChina, which bid $43.8bn for Syngenta, a Swiss company, is in poor financial shape. It made a net loss of Rmb889m in the third quarter of last year and carried a total debt of Rmb156.5bn ($24bn). The debt load was equivalent to 9.5 times its earnings before interest, tax, depreciation and amortisation at the end of 2014, well above the international standard for excessive leverage of 8 times ebitda.