SACRAMENTO -- As negotiations heated up in September over a bill to regulate hydraulic fracturing, commonly called fracking, oil companies poured millions into lobbying the California Legislature, quarterly reports released last week show.

The three interest groups that spent the most money from July 1 to Sept. 30 were oil and gas companies: Chevron ($1,696,477), Western States Petroleum Association ($1,269,478) and Aera Energy LLC ($1,015,534).

Nearly $13,000 of the Western States Petroleum Association's spending went toward hosting a dinner for 12 lawmakers and two staff members at The Kitchen, one of Sacramento's poshest venues.

Moderate Democrats seemed to be the target: Assembly members Adam Gray, Henry Perea and Cheryl Brown attended, as did Sens. Norma Torres, Ron Calderon and Lou Correa.

The dinner was held Sept. 4, as Senate Bill 4 by Sen. Fran Pavley, D-Agoura Hills, was awaiting a vote on the Assembly floor.

After the bill was amended, environmental groups withdrew their support. A week later, the bill passed the Legislature. Gov. Jerry Brown signed it Sept. 20.