A Senate committee abruptly postponed the final markup of the Reagan administration's trade reorganization bill yesterday because of demands by Democrats that it include new industrial policy provisions.

The Democrats want the measure creating a new Department of International Trade and Industry to be expanded to include their plan to set up a 20-member Council on Industrial Strategy.

Adding the industrial policy amendments to the bill could jeopardize White House support for what started out as one of the Reagan administration's major legislative thrusts in the increasingly important trade field.

The bill has been pushed by the administration, especially Commerce Secretary Malcolm Baldrige, as essential to government efforts to reduce the United States' record trade deficit. "We've always wanted a clear, clean trade reorganization bill, not a Christmas tree," said one administration trade official.

The White House has expressed its distaste for industrial policy, describing it as a Democratic political ploy that would lead to centralized government planning.

The bill's major sponsor, Sen. William V. Roth (R-Del.), chairman of the Senate Government Affairs Committee, was reported to be trying to work out a compromise with the committee's ranking minority member, Sen. Thomas Eagleton (D-Mo.), who drafted the industrial policy amendment. The Eagleton plan, co-sponsored by Sen. Carl Levin (D-Mich.), calls for the creation of a 20-member Council on Industrial Strategy representing business, labor and government.

Eagleton said last week that the present bill ignores the close connection between trade competition and the health of American industries.

The Eagleton move was seen as placing Roth in the tough position of risking the loss of either Democratic or administration support for his top legislative priority. Some administration trade sources questioned yesterday whether the Delaware senator would be willing to go further than the White House on the industrial policy issue in order to get his bill passed.