According to the agreement to join the bloc in 2007, Bulgaria's ban was set to expire on Jan. 1 and any move to break that deal would trigger EU infringement procedures.
However, Bulgaria, the poorest member of the EU, says land prices are still below those in more affluent states and that a surge in foreign demand would damage domestic farmers' ability to buy land.
"We must prevent the plundering of Bulgaria's most valuable resource," said Volen Siderov, leader of the nationalist, anti-EU, Ataka party, which brought the motion passed in parliament.
The Agriculture Ministry said last week that entrepreneurs from countries such as Qatar and Bahrain had expressed interest in buying Bulgarian land.
Currently, foreigners are allowed to acquire land in the country only through a registered Bulgarian company.
A spokeswoman for European Internal Markets Commissioner Michel Barnier said Bulgaria's accession treaty did not provide for any extension period on barring land sales.
"Therefore we expect Bulgaria to open its market in compliance with its commitments," Chantal Hughes told Bulgarian national radio.
"If Bulgaria wants the moratorium to remain in force after the beginning of next year, then it will have to receive support from all the rest of the EU member states. This means a review of the pre-accession treaty as well as re-ratifying by all the 28 EU member states."
Any such review could result in Bulgaria being targeted by reciprocal action by members states, potentially extending labour market restrictions on Bulgarians by other EU countries.
The question of potential EU punishment over the move had split the ruling coalition, which groups the Socialist Party and their junior partners, the ethnic Turkish MRF party. Prime Minister Plamen Oresharski had said extending the moratorium would be "impractical" because of the potential consequences.
Between them, they control 120 seats in the 240-seat parliament meaning they have to rely for a majority on the support of the Ataka party, which has 23 seats. Some 59 of the 84 Socialist deputies backed the motion.
The speaker of parliament, Mihail Mikov, a senior Socialist Party member, said the motion voted through by lawmakers did not comply with the constitution.
"Modern Bulgaria cannot take decisions on the basis of political populism," Mikov said.