WARSAW, Poland (AP) _ Prime Minister Zbigniew Messner called Thursday for speeding up efforts to reform Poland's troubled economy and announced a reshuffling of two key government posts.

In a speech to parliament, Messner said it was necessary to launch a new stage of the economic reform program to meet society's demands for ''an efficiently functioning, well-balanced ... healthy economy.''

''We must move away from half-measures, of taking small steps,'' said Messner. ''Similar changes are taking place in the Soviet Union and other socialist countries.''

He said there was no alternative to reform although some reform-linked austerity measures such as price rises might provoke protests. The government recently hiked prices for food, fuel and energy by from 10 to 50 percent.

The parliament, acting on Messner's motion, appointed Zdzislaw Sadowski, the chairman of the Polish Economic Society, as one of the country's five deputy premiers in place of Zbigniew Gertych.

Sadowski was an architect of the original economic reform program launched in 1982, and his appointment reflected an effort to give a stronger voice to supporters of economic changes in the state leadership.

Parliament also appointed Janusz Pawlowski to replace Stanislaw Gebala as minister of labor, wages and social affairs.

Messner said the new reforms would include measures to motivate workers by changing some state-run enterprises into joint stock companies in which employees could buy shares and giving incentive wage bonuses to directors who achieve good economic results.

Messner called for removing legal barriers to individual initiative and foreign trade, decentralizing the banking system, establishing a bond market and reducing the bureaucracy to limit interference in factories' operations.

At the same time, he said, the reform would involve austerity measures such as a more strict application of the bankruptcy law to inefficient factories and increased prices to reduce government subsidies for consumer goods.

''We do not conceal that speeding up the reform can cause social inconveniences,'' he said. ''Local protests ... may arise.''

Messner said detailed proposals that were drawn up by a special government commission would be published in newspapers Friday. He said the government could still amend the plans based on recommendations from official trade unions and other social organizations.