By Larry Fine

SPRINGFIELD, New Jersey (Reuters) - The third round of the PGA Championship was washed out on Saturday, as heavy rain and thunderstorms hit Baltusrol with 49 players yet to finish and the top 10 players still to tee off.

Players will return on Sunday to the drenched par-70 layout at 7 AM ET to resume play, with more threatening weather in the forecast.

The year's final major championship appeared to be heading for a Monday finish at best as Americans Jimmy Walker and Robert Streb, tied on nine-under-par 131, lead through 36 holes.

The PGA of America, however, laid out a plan to get the tournament completed on Sunday, saying the final round would begin at 8:40 AM ET in nine-minute intervals, staying in the same pairings as round three, starting from the first tee.

That ambitious plan would rely on no further weather stoppages.

Tournament chief official Kerry Haigh said that despite the forecast of storms on Saturday, and a similar forecast for Sunday, the decision was made not to play from two tees or in threesomes.

"It's a major championship and we certainly try and look at starting from one tee wherever we can," Haigh told reporters after play was called on Saturday.

"Unfortunately the weather didn't help us today. I think we have sort of a similar forecast for tomorrow. Our hope is that those showers or storms hit elsewhere.

"We do have Monday as an option, to continue into Monday if we need be. But our primary aim is to try and finish tomorrow evening."

Haigh said he doubted players would be allowed to lift, clean and place due to wet conditions.

"It's unlikely, very unlikely. The Rules of Golf are there to cover wet weather," he said, referring to such exceptions as standing water.

"It's a major championship, and we want it to be ran and perform as a major championship."

Haigh said the forecast called for it to be somewhat dry overnight, allowing the players to tee it up early on Sunday.

Two shots off the pace are world number one and defending champion Jason Day of Australia and 23-year-old Argentinian Emiliano Grillo.

Another stroke back lurks British Open winner Henrik Stenson of Sweden.

The last time the PGA was held at Baltusrol, in 2005, weather pushed the finish to Monday when Phil Mickelson birdied the 18th to claim victory.

(Reporting by Larry Fine; Editing by Andrew Both)