By Carolyn Said – This article was originally published in the SFGate. To read the full article, click here.

California regulators told Uber, Lyft and Sidecar that their new carpool options are a no-go because they violate a state law against charging different fares to passengers in a hired vehicle.

The companies and transit experts condemned the move as squashing an environmentally friendly option.

But it turns out that the California Public Utilities Commission, which sent warning letters to the companies last week, merely wants to spur them to get legislators to overhaul the law.

“Our hands are tied,” said Marzia Zafar, PUC director of policy and planning. “We wanted to make the letter public to let the (ride companies) and the Legislature know that there is this code. It may be outdated; it may not. The Legislature will have to review it and make a judgment call.”

Current law “strictly prohibits a charter party carrier from charging passengers on an individual-fare basis,” said the letters, available at http://tinyurl.com/lxmvh8n. “The commission lacks the flexibility to allow a transportation service that is contrary to the statute.”