Letter - No Obstacle to Regulation - NYTimes.com Re "Barriers to Change, From Wall Street and Geneva" (Fair Game, March 18), which described the agreement on financial services among members of the World Trade Organization: The agreement is about opening markets, not tying governments" hands when it comes to regulating their financial services sectors. The most important elements of the W.T.O. commitments on financial services pertain to nondiscrimination and national treatment, meaning that if you accept opening your market, you may not apply different regulations to banks from different foreign countries or to your local banks. Open trade in financial services does not mean greater risk to the system's safety and soundness. As members of the European Union, Britain and Sweden provide the same degree of market access to foreign providers of financial services. Yet the crisis did not hit Swedish banks, while British banks suffered greatly. Their regulatory systems differ. The W.T.O. does not provide broad global rules for financial regulations. But it does not stifle governments" ability to respond to financial crises, either. Keith M. Rockwell Geneva, March 19 The writer is director of the information and external relations division of the World Trade Organization.