Letter of greek alphabet
Flag
Company
Country
Finbeta
Italy
Goulandris Brothers, Piraeus

blue flag, white Greek "Gamma"("G")

Greece
General Steam Navigation Company of Greece
Greece
Goulandris Brothers Greece
Fr. Fragoudakis S.A (Fragline), Athens

Greek letter Gamma for George and the Greek letter Phi for Fragoudakis.

Greece
C. M. Los (London) Ltd., London

triband BWB, in center red turned "V" (= greek letter Labda (L))

UK
Livanos, Chios
Greece
M.G. Livanos, Piraeus
Greece
Olympic Maritime S.A., Monte Carlo
Monaco
Olympic Maritime
Greece
Fafalios Shipping S.A., Piraeus
Greece
Fairsky Shipping and Trading Greece
Andreadis (U.K.), London

white flag, red saltire, blue oval and vertical bar.

(Obviously of Greek origin: the blue oval and stripe form together the Greek letter "Phi" - F)

UK
Frixos V. Papachristidis, London

blue with a kinda WBW Scandinavian cross; in center white disk with inner blue circle containing Greek letters "FVP" (Phi - Beta - Pi).

UK
Hellespont Group
Greece
L & W Shipping Agency S.A. (A.S. Polemis), Piraeus
Greece
G.N. Pittas Greece
Polembros Maritime Co., Ltd. (S. Polemis), Piraeus
Greece
Remi Maritime Corporation Greece
Papachristidis Co. Ltd.
Greece
Unknown Unknown
Sitinas Enterprises S.A., Athens

horizontal 5-band of blue and white; in center red 5-pointed star, white "Sigma".

Greece