ATLANTA (Reuters) - Pacific trade ministers are optimistic of closing a sweeping Pacific Rim trade deal after progress on Friday on hurdles involving autos, dairy products and intellectual property protections for expensive biologic drugs.

Ministers represented in the Trans Pacific Partnership (TPP) talks in Atlanta met for 20 minutes before breaking for negotiators to resume work on specific issues, work that Japan's Economy Minister Akira Amari said on Friday would likely go on all night.

The United States and Australia are locked in intense negotiations over the length of time pharmaceutical companies have exclusive rights to produce and market next-generation medicines.

Australia is one of a group of half a dozen countries resisting a U.S. push to set a standard of eight years protection and see five years as a red line.

Amari said talks on the issue of biologic drugs "were centered on the United States and Australia" and that negotiators were "putting their heads together" to try to find an agreement.

On the third day of talks, major progress had been made on another key sticking point, the auto trade involving Japan, Canada, the United States and Mexico, Amari said, noting countries were "one step away from completion".

He said that Mexico, Canada and Japan had neared terms of a deal on increased dairy market access and that the remaining issues involved New Zealand and the United States.

WRAPPED UP BY SATURDAY?

New Zealand, which has 17 percent of global dairy trade, making it the largest exporter, has been pushing for improved access for its exports as part of the TPP.

But the United States is unwilling to allow in more imports unless its farmers in turn secure better access for exports in Canada and Japan.

"I think the remaining issues are between New Zealand and the United States," Amari said of the talks involving dairy trade.

Negotiators hope to wrap up Trans-Pacific Partnership talks by Saturday when a joint news conference by all 12 ministers has been scheduled.

Mexican Economy Minister Ildefonso Guajardo joked that he was confident enough to bet money on wrapping up the deal, which would establish a free trade zone covering 40 percent of the world economy, on Saturday.

"I think that the dynamics are very positive," he told reporters.

(Reporting by Kevin Krolicki; Additional reporting by Kevin Fogarty; Editing by Ken Wills and Richard Borsuk)