With a large number of countries expressing objections to their exclusion from the core group of seven nations at the Doha Round of trade talks here, India today called on WTO to expand the network.

"I have said that the group (of seven countries) should be expanded. There has to be a transparent process at the end of the day. We don't represent all countries in the world," Commerce and Industry Minister Kamal Nath told newspersons at WTO headquarters here.

The seven countries -- India, Brazil, the US, the EU, China, Australia and Japan -- are part of different groups constituted by WTO chief Pascal Lamy to narrow differences on specific issues in agriculture and industrial goods negotiations.

Earlier in the day, countries like Switzerland, Kenya, Indonesia, Turkey, Egypt and Chinese Taipai had expressed their "frustration" over the format of the core group.

Expressing doubts on the composition of the group, Switzerland has lodged a formal complaint with the WTO, saying it would not serve the country's interest at the trade talks.

"You called ministers for negotiations in Geneva. You asked us to take time, to put our energy in the process, to negotiate. However, you changed the process and decided to work in one very small group only.

"By doing so, you have put many of us Ministers in the waiting room -- which creates political problems for me at home and many of colleagues are in the same situation," Swiss Federal Councillor D Leuthard said in a letter to the WTO.