Under the plans, online gaming would most likely remain free, but other unspecified premium services would start carrying a charge to access.
In a statement issued to CVG, Hirai said: "SCE will further increase sales by offering users new entertainment through the combination of hardware, software, peripheral and PlayStation Network.
"Especially in the online area, we are studying the possibility of introducing a subscription model, offering premium content and services, in addition to the current free services."
Hirai decided to speak publicly on the plans following the leak of a Sony slide presentation outlining the firm's aim to generate a "new revenue stream from subscription".
The presentation further revealed SCE plans to position the PS3 as a 3D-ready console as part of an overall strategy to introduce the technology into Sony consumer electronics during 2010.
Towards the aim, all current PS3 consoles will be upgraded to 3D via a firmware update at some point in the future.