Shares of P&G, the world's largest consumer products maker by market value, rose more than 3 percent in after-hours trading, indicating some investors welcome Peltz's effort to shake up the company's management and improve financial results.

A new preliminary vote tally prepared by independent election inspector IVS Associates after four weeks of recounting from last month's proxy contest showed Peltz won by 43,000 shares voted out of 2.6 billion, according to a source.

That leaves Peltz with a margin of victory of 0.002 percent of outstanding shares, which analysts said is so slim it could easily flip again.

"Shareholders have voted, and they have indicated that they want Nelson Peltz to join the Board," Peltz said in a statement where he urged the company to accept the inspector's tabulation and "not waste further time and shareholder money contesting the outcome of the annual meeting."

P&G said in a statement the results are still preliminary and "subject to a review and challenge period."

P&G and Peltz's Trian Fund Management, which has a $3.5 billion stake in the company, now both have the chance to recount the votes themselves and challenge the outcome, which means a resolution could still be weeks away. This phase of the contest is known as the "snakepit" in industry circles.

IVS's tally was delayed several times suggesting the inspector was being especially careful with this high-profile fight. The tally may also have taken longer because roughly 40 percent of P&G's shareholders are retail investors.

The recount tally is an embarrassing setback for P&G after the company claimed a narrow victory in last month's vote. It is the latest twist in the largest proxy battle in history, in which the two sides collectively spent more than an estimated $100 million on mailings, phone calls and advertisements to woo investors.

Erik Gordon, a law and business professor at the University of Michigan said if the vote holds and Peltz gets a seat, management will have to make changes more quickly. "Peltz won't try to remove (the CEO), but Peltz won't forget how much money he spent trying to bar the boardroom door. The pressure on the CEO to grow the business goes up and the timeline gets shorter."

For his part, Peltz said he would work collaboratively in the boardroom and said before the election he would propose bringing the incumbent director he beat back onto the board.

Trian wages few proxy contests and lost two years ago at DuPont but within months the CEO was replaced. In 2006, Peltz eventually won a seat on the board of Heinz after both sides initially claimed victory and IVS had to tally the votes.

(Reporting by Vibhuti Sharma in Bengaluru and Svea Herbst-Bayliss in New York; Editing by Bill Rigby and Chris Reese)

By Svea Herbst-Bayliss and Vibhuti Sharma