UPDATE 1-S.Korea to sell 7 pct stake in Woori in Nov -Yonhap

* Block trade to take place after Oct. 29 quarterly results

* Deal estimated at $800 mln

(Adds estimated value, background)

SEOUL, Oct 27 (Reuters) - The South Korean government is planning to sell part of the stake in Woori Finance Holdings (053000.KS) in a block trade next month, Yonhap news reported on Tuesday, a deal estimated to fetch about $800 million.

The prospective sale will come as the government is trying to retrieve public funds used to bail out Woori, the country's No. 3 banking group and other ailing companies in the aftermath of the Asian financial crisis in the late 1990s.

"To help investors' judgement, (the government) will start selling 7 percent of Woori Finance Holdings shortly after its third-quarter results are released on Oct. 29," a senior official of the Public Fund Oversight Committee was quoted as saying.

The committee was launched this year to speed up the sale of restructured companies, including Daewoo International (047050.KS) and Ssangyong Engineering & Construction (012650.KQ) to make up for a tax income shortage.

The government owns 73 percent of Woori (WF.N).

Earlier this month, a senior government official said market conditions have improved for the government to offer a stake in Woori and the government would make a decision to sell 7 percent of Woori within this year. [ID:nSEO165149]

The stake on offer is worth 945 billion won ($801 million), based on Monday's closing price.

Yonhap said that after the 7 percent stake sale was completed, the government would decide how to sell another minority stake of 16 percent in the financial group. It wants to put up for sale 50 percent plus one share in Woori to a strategic buyer.

($1=1180.4 Won)

(Reporting by Kim Yeon-hee; Editing by Ken Wills)