The Commission, which oversees trade policy for the 28-member European Union, has already set a quota and tariff system to counter concerns that steel products no longer exported to the United States will instead flood European markets.
The "safeguard" system is provisional pending the conclusion of the Commission's investigation, which was due to have ended nine months after its start on March 26.
However, EU rules allow it to extend an investigation by up to two months in exceptional circumstances. The Commission said the size of the investigation, with 28 product categories and over 800 interested parties registered, was unprecedented.
The Commission said in the EU official journal this counted as exceptional circumstances. The fact that temporary measures were already in place meant an extension would not have a negative impact.
Definite measures, if they are to be adopted, would now have to be in place by Feb. 1.
The current safeguards involve quotas for different steel products, set at the average of imports for the past three years, with a 25 percent tariff set for volumes exceeding these amounts.
ArcelorMittal, the world's largest steelmaker, said last week it was "absolutely" critical that Europe extend the protection measures and remedy weaknesses, such as exemptions for developing countries.