Rio Tinto chief Tom Albanese pledged a closer relationship with China, saying it is of great importance to the company.

"From a more personal perspective, I am committed to building our relationship with China," Albanese said, as quoted by Australian Associated Press on Thursday.

Despite recent arrests of Rio Tinto's staff in China and the failure of a deal with a Chinese aluminium group, Albanese said China was still Rio Tinto's largest customer and he wanted to rebuild ties with the country.

He welcomed the less severe charges against the four Rio Tinto staff, including Rio executive and Australian citizen of Chinese origin Stern Hu, from the previous suspicion of stealing state secrets down to commercial espionage.

"We do welcome the fact that the grounds for their arrests do not seem to be as serious as early reports had suggested," Albanese told reporters in London during a webcast.

He said the care for the company's detained staff was the first priority, and he was pleased to see they had been treated well, they were in good health and their families had legal teams in place.

Rio Chairman Jan du Plessis also said Rio would respect the Chinese law on the case. He emphasized that Rio was unable to go into detail on the allegations.

"I am naturally personally concerned about them, but I want to stress that we will respect the Chinese legal process," du Plessis said in London.

Relations between Rio Tinto and the Chinese government have been strained since the arrest of four Rio Tinto employees on July 5, including Rio chief of the Shanghai office Stern Hu.

Rio Tinto's failed 19.5-billion-U.S. dollar business deal with Aluminum Corporation of China (Chinalco) has also put pressure on the relationship with China.

Albanese said he was disappointed to see they did not ultimately come to a deal with Chinalco, Rio Tinto still sees opportunities to work with Chinalco and has had some early discussions with them.

Currently Rio Tinto is still negotiating the iron ore prices with China, while Australia's Fortescue Metals had just reached agreements with the China Iron and Steel Association (CISA) on Aug. 17 on discount iron ore prices.

China is Australia's biggest export market, with a two-way trade volume of 53 billion U.S. dollars last year. Australia mainly exports iron ore, wool, copper ore and manganese to China in 2008.