* Shell sells stake to help pay off debt, CFO says
* Shell now at $25 bln of $30 bln asset sale target (Recasts with full stake sale, adds analyst comment)
LONDON/SYDNEY, Nov 13 (Reuters) - Royal Dutch Shell on Monday sold its entire stake in Australia's largest independent oil and gas company Woodside Petroleum Ltd for $2.7 billion as it pushes ahead with its vast disposal program.
Shell, which has been slowly divesting its Woodside holding, initially said its Shell Energy Holdings Australia Limited (SEHAL) unit had struck a deal with two investment banks to sell 71.6 million Woodside shares for A$31.10 ($23.79) apiece.
Several hours later, the Anglo-Dutch company said in another statement that "following strong demand from institutional investors," SEHAL upsized its sale to 111.8 million shares worth a total of $2.7 billion before tax proceeds.
That represented 13.28 percent of Woodside shares and the entirety of SEHAL's shareholding in the company, it said.
Shell shares were up 0.8 percent at 1525 GMT. The announcements came after the close of trade on the Australian bourse, where Woodside ended 1 percent lower at A$32.24 a share.
With the Woodside deal, Shell has so far sold or agreed to sell nearly $25 billion as part of a three-year, $30 billion asset sales program launched following the acquisition of BG Group in 2015.
"Proceeds from the sale will contribute to reducing our net debt," Shell Chief Financial Officer Jessica Uhl said in the initial statement.
Analysts at investment bank Tudor, Pickering, Holt & Co said that Shell's $30 billion target "is easily within reach and we see the potential for this to be increased at the Management Day" on Nov. 28.
A sell down of Shell's 98 million shares in Canadian Natural Resources, worth around $2.8 billion "is only a matter of time," TPH said in a note.
Equity capital markets teams from a number of international banks had been asked earlier on Monday to submit bids and lock in cornerstone investors, a banking source requesting anonymity told Reuters.
Even before Shell set out to sell assets, it was distancing itself from Woodside.
In November 2010, it sold 10 percent of the issued capital of Woodside, taking its stake to 24.27 percent. This was further diluted to 23.08 percent after Shell decided not to participate in Woodside's dividend re-investment program.
In June 2014, Shell sold another 9.5 percent of Woodside's issued shares, dropping its interest to 13.28 percent after again opting out of the dividend reinvestment scheme.
Australia blocked a takeover bid by Shell for Woodside in 2001 on national interest grounds.
Shell will remain joint venture partner in two liquefied natural gas projects in Australia, according to Woodside.
"Woodside will maintain a close working relationship with Shell - as a joint venture partner and customer of Shell technology - and we recognize that Shell will always be part of our history," Woodside Chief Executive Peter Coleman said in a statement.
($1 = 1.3074 Australian dollars) (Reporting by Radhika Rukmangadhan in Bengaluru, Ron Bousso in London and James Regan in Sydney; Editing by Mark Potter and David Evans)