The 10-nation European Common Market today denounced U.S. plans to file six antidumping suits against European steelmakers and told the Reagan administration to stop blaming Europe for the woes of the American steel industry.

"The European Commission was extremely disappointed to learn of the intention of the U.S. Department of Commerce to take a step that could lead to countervailing duties against steel exports from France and Belgium," said a statement from the commission, the Common Market's executive branch.

Noting that the U.S. decision was made in the midst of diplomatic discussions on the issue, the statement added, "The American authorities preferred to take a dangerous and disputable path."

The Common Market was reacting to Commerce Secretary Malcolm Baldrige's announcement to the Senate Steel Caucus on Thursday that cases would be filed against several foreign steelmakers.

Baldrige said some of the cases would involve major subsidization of companies by European governments and some would involve dumping, or selling steel in the United States at prices below production costs.

"I cannot say at this time what countries are involved because we are formally notifying them through their embassies," said Baldrige, citing a provision in the 1979 Trade Act requiring such action. "We will be announcing the cases early next week," he added.

The secretary said most of the suits will deal with dumping imported carbon steel plates and one will deal with subsidies for hot-rolled sheet steel.

Baldrige also said the Commerce Department will release results of its investigation of unusual import increases, or "surges," in recent months. The study will be completed by Nov. 18 and probably will result in "one or more" government suits.