The move is another victory for Connectix in a legal battle that it has been fighting with Sony since early 1999.
Virtual Game Station is a software emulator that lets a Mac run games designed for the PlayStation.
Roy McDonald, president and chief executive officer of Connectix, said: "It was entirely expected and what we anticipated. The case is starting to wind down a bit, I think. I hope Sony will see it's better to join us than fight us."
With the latest move, Sony has withdrawn 11 patent claims that were part of a second suit filed against Connectix. Seven of nine claims were previously withdrawn from the first, leaving the remaining two to be put before a hearing scheduled for September 1.
Whittled down McDonald said: "In the first lawsuit, seven of the nine are gone. Of the two, one was to do with trade secrets, and it was sufficiently unclear to the judge that he decided to take another 90 days to clarify, which doesn't sound to me like there is much of a strong case. The other is to do with interference with contract, and there is no basis for that unless the other claims succeed."
Benjamin Gurnsey, a spokesman for Sony, confirmed the withdrawal of the claims, but could offer little more information. He said: "We have voluntarily dismissed those claims as they are in that state." He was unable to clarify whether the claims would be resubmitted in a further lawsuit or if they have been completely withdrawn.