The European Commission has backed Meglena Kuneva to be the new commissioner from Bulgaria, but has yet to approve Romania's candidate.
Bulgaria's nominee gets the kiss of approval in Brussels
The two countries will have one commissioner each when they join the European Union in January 2007.
Ms Kuneva is Bulgaria's minister for Europe and is set to receive the EU consumer protection portfolio.
Romania's choice for EU commissioner, senator Varujan Vosganian, has yet to get the green light from Brussels.
"Consultations on the Romanian commissioner's nomination are still under way," the commission said.
Romanian Prime Minister Calin Tariceanu confirmed his support for the National Liberal Party senator as the government's choice for commissioner.
But after meeting European Commission president Jose Manuel Barroso on Thursday, Mr Vosganian returned to Bucharest without being officially nominated by him.
Mr Vosganian has been criticised in the Romanian media for his connections to a controversial business tycoon.
The Socialist group in the European Parliament, which must approve Mr Barroso's nominations for commissioners, has expressed doubts about Mr Vosganian's credentials.
"As far as the Romanian candidate is concerned, it is clear that we will have to explore his European profile but also his acceptance of European standards and European values," the Socialists said.
Ms Kuneva, 49, is expected to be easily approved by the MEPs. She is set to take charge of consumer policy, which is becoming a separate portfolio.
The current commissioner in charge of consumer protection, Markos Kyprianou, will now focus on health.