His Marmaras Navigation has picked up the 56,600-dwt pair Hanjin Rostock and Hanjin Albany (both built 2011), brokers say.
A price of $13m has been placed on each of the vessels by independent shipbroking sources.
This compares with the $15.34m placed on the supramaxes by VesselsValue.com.
Marmaras officials could not be reached for comment today.
Diamantides has a fleet of 19 bulkers under the Marmaras umbrella.
He also boasts a fleet of 26 tankers, including two newbuildings, under the banner of Delta Tankers.
The deal marks the first second-hand move for Marmaras since late 2013.
Delta has been active more recently, taking a suezmax from Liquimar earlier this year.
It paid $56.5m for the 166,100-dwt Ariadni (built 2009) at the same time as it welcomed a pair of newbuildings.
