President Mikhail Gorbachev tried Friday to restore order to the chaotic Soviet economy, nullifying decisions by the republics and local officials that have disrupted food supplies.

He also decreed that government enterprises must carry out all contracts through the rest of this year and the first quarter of 1991 to ensure a steady flow of supplies.His move represented a crackdown on those regions that have broken the discipline that for years has guided the Soviet Union's economy.

Parliament has pressured Gorbachev to improve food supplies, particularly in Moscow and Leningrad, where state stores have little milk, sugar, eggs, butter, cheese and meat. Some right-wing lawmakers demand a state of emergency.

Moscow city officials accuse surrounding regions that usually supply the capital with food of reneging on contracts and stopping deliveries.

Gorbachev's presidential decree, "On Combatting Disorganization of the Soviet Economy," was read Friday night on Soviet television.

In it, Gorbachev complained that government economic decisions "have not been carried out."

He declared "null and void all economic decisions by local and republic bodies that undermine normal trade." He also ordered local and republic officials to reverse decisions to stop supplying Russian regions and Moscow.

The decree ordered the government to apply tough sanctions on exporters who fail to secure proper licenses and contracts to sell raw materials and other goods abroad. This appeared aimed at preventing any of the 15 republics from signing contracts with foreign firms to export resources without central government consent.