UPDATE 1-Bank of England says to start buying corporate debt on Sept. 27

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LONDON, Sept 12 (Reuters) - The Bank of England said it would start to buy 10 billion pounds ($13.3 billion) worth of sterling corporate bonds via reverse auctions on Sept. 27, as part of the economic stimulus measures it announced last month.

The BoE said it planned to hold three auctions a week initially, and would spread its purchases over 18 months.

The central bank announced the bond purchase plan on Aug. 4, alongside 60 billion pounds of government bond purchases and its first cut in interest rates since 2009, to tackle the immediate economic cost of June’s vote to leave the European Union.

Bonds needed to be issued by firms that make a significant contribution to the British economy and that were not part of the financial services sector, the BoE said on Monday.

Auctions will take place on Tuesdays, Wednesdays and Fridays and will focus on particular sectors.

The central bank said it aimed to buy bonds so that its holdings were representative of the British corporate bond market as a whole.

Based on debt currently in issue, this would mean 25 percent of bonds would be from electricity companies, 15 percent from non-cyclical consumer companies, 14 percent from the industrial and transport sector and 13 percent from communications firms.

Smaller percentages would be bought from cyclical consumer companies, utilities and property businesses.

“Corporate bonds issued by firms regulated by the Bank - such as banks, building societies, and insurance companies - will not be eligible,” the BoE added. ($1 = 0.7516 pounds)

Reporting by David Milliken; editing by Kate Holton, Larry King