The commission said the nine producers had refused Taiwan Power Co's request to renegotiate electricity prices, the Taipei Times reported.
"The total fine is the highest in the commission's history because we wanted to inflict a high cost on companies that commit such wrongdoing," FTC Chairman Wu Shiow-ming was quoted as saying.
The report said the case relates to individual contracts signed by the nine IPPs from 1999 to 2006 to sell power to Taipower.
The commission said that in 2007 and 2008 the companies renegotiated prices with Taipower to reflect rising procurement costs, which the commission said helped raise their profits from that period to 2011 by $653 million.
However, the report said Taipower during talks from 2007-12 had sought price adjustments to reflect lower interest rates but the request was rejected. The commission said that caused Taipower to spend more on electricity purchases from 2007-11.
The Times quoted the commission as saying the IPPs had colluded to sabotage the negotiation process.
The report didn't say if the IPPs responded to the fines.