BRUSSELS — The European Union’s executive arm announced plans on Wednesday aimed at stopping its countries from striking bilateral deals that cede too much power to oil and gas exporters like Russia.

Europe needs to look “beyond its borders to ensure the security of energy supplies” and “act together and speak with one voice,” the European Union energy commissioner, Günther Oettinger, said at a news conference.

The proposal represents a bid by the authorities in Brussels to take more control over a sector where countries zealously guard their sovereignty and where powerful utilities still dominate a number of crucial markets.

Mr. Oettinger said he wanted the right to demand information on energy deals involving member states and third countries before such deals are signed. Under the plan, the European Commission, the union’s executive arm, would publicize any concerns. If those concerns were ignored, the commission could sue member countries to change the terms of any agreements that threatened to jeopardize the union’s overall energy security.