WITH EXCEPTIONAL harmony and vision, the government of the United States has acted to transform a glaring eyesore in the center of its capital city into a crowning jewel of the Federal Triangle -- bringing new life and even more grandeur to the "Avenue of the Presidents." Where a functional but ugly parking lot now abuts the District Building, there is to be an International Cultural and Trade Center of monumental proportions and great versatility of use.

By all accounts, including those of the federal Treasury, this Pennsylvania Avenue project is a plus. It is to be built under a relatively novel arrangement: the General Services Administration will sign a 30-year master lease for the office space, which is to be used as collateral to obtain financing. A private developer, selected competitively, will build the project and own it for the life of the lease, when it will revert to the government. This is estimated to save the government a good $270 million rent on its way to taking title. The center itself will be a home for international trade offices and pertinent U.S. agencies as well as a showcase for exhibits and performers from every continent, along with boutiques, restaurants and out-of-sight, instead of unsightly, parking -- with more spaces than there are now.

To fulfill this commitment to function and flair, the president must appoint a 15-member commission. The members should be distinguished, nonpartisan and determined to guide the project speedily through a series of plan approvals that had best be completed by midsummer 1988. The unanimous consent of both houses of Congress and presidential support for this history-making endeavor should not be squandered by bureaucratic delays.