Swiss President Doris Leuthard Thursday said the rise in bilateral trade between Switzerland and China is a delightful surprise, as she seeks to expand economic cooperation with China through a free trade agreement.

The trade increase was a surprise as it came during the economic crisis last year, Leuthard said.

In the first six months of 2010, Swiss exports to China increased more than 30 percent and Chinese exports to Switzerland increased more than 16 percent.

Total trade volume between the two countries during the period hit 6.2 billion Swiss Francs (5.86 billion U.S. dollars), she added.

Leuthard said she is optimistic about the future of Sino-Swiss bilateral trade, as the two countries are working on a free trade agreement.

"We are ending feasibility study (for the agreement) so both sides know the market, the opportunities and the risks very well. It is very promising," she said.

After the joint feasibility study, the two sides will enter the final stage ahead of the signing of the deal, she added.

Talks on the free trade agreement began in 2007 when Leuthard, as head of the Federal Department of Economic Affairs, signed an agreement with then-Minister of Commerce Bo Xilai. The agreement recognized the full market status of China.

Switzerland hopes to be the first European country to have a free trade agreement with China, Leuthard told Xinhua in an interview last year.

China is Switzerland's second largest trade partner in Asia after Japan.