Special to The New York Times.

HAVANA, Oct. 8--Rumors circulated by opposition sources in Havana that Dr. Joaquin Martinez Saenz, president of the National Bank of Cuba, will not return here for a long time and suggesting some divergence of opinion between him and the administration were denied today by a spokesman of the National Bank.

The spokesman said Dr. Martinez Saez went to Europe on the invitation of the Belgian Government in connection with trade matters between Cuba and Belgium.  Now he has accepted an invitation to be the guest of honor of the Madrid Chamber of Commerce.  He is scheduled to return here Oct. 20.