A 17-page document, advocating sweeping reforms in Soviet economic and political institutions, has been leaked to some western news organizations here.

The report, entitled "To the Citizens of the U.S.S.R.," calls for a western-style political system with competing organizations and economic reforms that go beyond those introduced by Communist Party leader Mikhail Gorbachev.

The document, whose authors are unknown, was first made available to the British newspaper The Manchester Guardian, and to NBC-TV.

The Guardian yesterday described the document as a "manifesto" drafted by a group of "party and government officials of senior rank." But the language and tone were more reminiscent of samizdat, self-published reports circulated by dissidents.

The document says the Soviet economy is dragging up to 15 years behind the West, that the Soviet standard of living is one of the lowest in the world, in some cases, and is in danger of falling even further behind.

It warns that the Soviet foreign debt to the West, now $30 billion, is likely to multiply sixfold in the next 15 years unless drastic steps are taken. The paper links political freedoms and the performance of the Soviet economy.

The author of the report is unknown, as is the way it was passed to western journalists and whether officials were involved in the preparation of the report.

The dire picture of the Soviet Union's economic prospects, and the advocacy of a full and open flow of information and freedom to join political organizations are not consistent with the language senior Soviet officials use.

Some western observers familiar with the document speculated that it could be the result of the ongoing campaign for openness, encouraging individuals and media organizations to speak out.

NBC correspondent Steve Hurst said in a broadcast last night that he received the document, 17 pages typed in Russian, through an intermediary who told him it came from a senior Soviet official.