While there is a chance production offices across town won’t be shut down tomorrow morning and picket lines won’t go up, a source close to the studios also wasn’t optimistic about a writers strike being averted. “We tried to make progress with our last proposal, but the other side is not receptive it seems,” the executive lamented.

After positive signs over the weekend, including an increased offer by producers reps the AMPTP for employer contributions to the health plan of more than $85 million over three years, negotiators for the studios and WGA have been sequestered since 11 AM today at the AMPTP headquarters in Sherman Oaks, CA after a rare Sunday bargaining session. There also was reportedly a move made in the area of compensation for writers employed on short-order TV series – one of the WGA’s main priorities in the talks.

Despite the progress, the two sides are not closing in on a deal, sources cautioned today.

There is still time — the current WGA contract does not expire until midnight PT tonight, and the two sides could conceivably opt for a short-term extension (usually by 24 hours) if they are close enough to the finish line.