CBS’ The Big Bang Theory is a big step closer to making the new August 6 production start date for Season 8 — I’ve learned that stars Jim Parsons, Johnny Galecki and Kaley Cuoco have agreed to new three-year contracts. The deals for Parsons, Galecki and Cuoco came after marathon negotiations between Big Bang producer Warner Bros. TV and reps for the actors over the weekend, with Parsons’ pact closing first on Sunday, followed by the Galecki and Cuoco deals under “favorite nations” terms, giving the trio financial parity. WBTV declined comment and reps for Parsons, Galecki and Cuoco could not be reached for comment, but I hear the trio are in the long-rumored Friends salary territory, scoring paychecks of $1 million per episode for the 72 episodes the show is slated to produce in Seasons 8-10. What’s more, I hear the door has been left open to a potential 11th season.

I also hear that the complex deals go well beyond per-episode fees and also include larger pieces of the show, signing bonuses, production deals and advances towards the back-end — perks associated with talent deals on shows as big as Big Bang. In addition to tripling their most recent salaries of $350,000 an episode, I hear Parsons, Galecki and Cuoco also quadrupled their previous ownership on the show, which has gone up from .25 point to more than a point. I hear Parsons’ pact includes a production deal that spans TV and features and possibly theater, with Galecki and Cuoco also getting producing arrangements. Galecki produced a comedy project for WBTV last season, No Place Like Home, which went to pilot at Fox. All in, I hear Parsons, Galecki and Cuoco are poised to make at least $90 million dollars each over the lives of the deals, with some observers noting that the total could conceivably rise towards $100 million if Big Bang continues to be as strong in syndication and auxiliary markets. With the big payday for Parsons, Galecki and Cuoco and the windfall for top profit participants, WBTV still is expected to clear $1 billion in profits, with some projecting that Big Bang could contribute to Time Warner’s bottom line twice that over its lifespan.

With Parsons, Galecki and Cuoco signed on and co-stars Melissa Rauch and Mayim Bialik already on board for Season 8 after renegotiating their contracts last fall, the focus is on wrapping negotiations with the last remaining original cast members, Simon Helberg and Kunal Nayyar, before the table read planned for Wednesday. I hear the two are close and there is a possibility for them to reach new deals today though there have been some bumps in the back-and-forth. The close friends, who raised their per-episode fee to more than $100,000 an episode in the 2010 renegotitions, are once again negotiating together and had been looking to close the salary gap with fellow original cast members Parsons, Galecki and Cuoco. If Helberg and Nayyar close on time for the Wednesday table read, production on Season 8 will be only one week behind schedule, a delay that the actors and WBTV are hopeful they can make up later in the season so the order remains 24 episodes and is not trimmed down to 23.

Big Bang, whose eighth season is slated to kick off with an hourlong premiere on Sept. 22, is a major piece of CBS’ fall plans. It is first being used on Monday as an 8 PM anchor and a launch pad for new drama Scorpion before the comedy returns to Thursday post-football to once again lead the network’s comedy block.

The blockbuster deals for Parsons, Galecki and Cuoco were brokered by attorneys from Gang, Tyre Ramer & Brown (Parsons) and Hansen, Jacobson, Teller (Galecki, Cuoco) as well as the trio’s other reps, CAA and Principal Entertainment (Parsons), WME and Management 360 (Galecki) and SDB Partners and Brillstein Entertainment Partners (Cuoco).