Special to The New York Times

WASHINGTON, Oct. 27- The State Department denied today charges by Fidel Castro, Cuban rebel leader, that the United States was intervening in the Cuban civil war.

Meanwhile, the department was accused be Señor Castro’s foes of bypassing the Cuban Government in negotiating directly with rebel elements and “according the rebels an international status to which they are not entitled.”

This charge was made in a prepared statement to the press by John E. Kieffer, president of Universal Research and Consultants Inc., registered agents for the Republic of Cuba.

In replying to the Castro charges, made in a rebel broadcast yesterday, Lincoln White, State Department press officer said:

“We have carefully avoided any such intervention and there is certainly intention on our part to alter this policy.”

Mr. White described his blunt statement of last week, which threatened action by the United States if two Americans kidnaped by rebel forces were not released, as part of a general policy “designed to protect the lives of American citizens.”

U.S. Accused of Plotting

Señor Castro also charged yesterday that Earl E. T. Smith, United States Ambassador to Cuba, was “plotting” with President Fulgencio Batista to accomplish direct United States intervention in the Cuban hostilities.

Mr. Kieffer’s statement said that “United States diplomats working in Cuba have on many occasion negotiated directly with rebel elements.”

“This direct dealing”, it assertely “is not only and insult to the Batista government but contrary to all the accepted practices and usages in modern diplomacy.”