China expressed surprise on Sunday at Mexico's decision to revoke a $3.75 billion high-speed rail contract from a China-led consortium, saying the Chinese company involved had strictly followed the bidding procedure.

After the contract to build the link was awarded on Monday, Mexican opposition politicians accused the government of favoring the group led by China Railway Construction Corp Ltd (601186.SS), the sole bidder.

Mexico's Communications and Transport Ministry, which has defended the bidding process, said on Friday it expects to re-run the tender in late November under the same terms, and would keep it open for six months to enable all interested parties to participate.

China's official Xinhua news agency, citing an unnamed spokesman from powerful economic planner the National Development and Reform Commission, said Mexico's decision was "because of domestic factors".

"It had nothing to do with the Chinese enterprise, and the Chinese government hopes that the case could be settled properly as soon as possible," the spokesman said.

"It is surprising to hear Mexico decided to scrap the rail deal as the Chinese enterprise has been strictly following the public bidding procedures and requirements, and the bidding content complies with the requirements of the Mexican government," he added.

"The Chinese government encourages enterprises to participate in infrastructure construction in Mexico in a mutually beneficial way, and hopes the Mexican government could create a fair competition environment for these enterprises."

The decision was made ahead of a state visit to Beijing by President Enrique Peña Nieto, who will also be attending the Nov. 10-11 Asia Pacific Economic Cooperation summit.

Since Peña Nieto took office in late 2012, he has tried to forge closer ties with China after years of rivalry between the two countries seeking to supply the U.S. market.