Britain will have to sell 11.4 billion pounds more in government bonds than originally envisaged in the current 2011/12 fiscal year, after a sharply lower growth outlook forced Chancellor George Osborne to revise up his borrowing forecasts.

The Debt Management Office said gilt issuance in the current fiscal year would rise to 178.9 billion pounds from the 167.5 billion pounds it pencilled in earlier this year, well above analysts' forecasts for a figure of 171 billion pounds.

Following is a breakdown of the DMO's revised gilt issuance remit. - Short conventional +3.2 bln stg to 60.6 bln stg (33.9% of sales) - Medium conventional +5.1 bln stg to 39.8 bln stg (22.2% of sales) - Long conventional +2.1 bln stg to 39.5 bln stg (22.1% of sales) - Index-Linked +1.0 bln stg to 39.0 bln stg (21.8% of sales)

The DMO said it would hold two additional gilt auctions, one for a short conventional gilt and one for a medium-dated conventional gilt. It said the first additional auction would be on December 14 for a medium-dated gilt, but not the 3.75 percent 2021 bond.

The other additional auction will be held on January 11.

In addition, the DMO said it is postponing by one week the mini tender scheduled for the week starting December 12.

The DMO also said that following a consultation with investors, it had decided not to issue index-linked gilts linked to CPI inflation in the 2012/13 fiscal year.

The government judges that issuance of CPI-linked gilts in the near term would be unlikely to be cost-effective and would involve a number of risks, the DMO said in a statement.

The decision not to issue CPI-linked gilts in 2012/13 does not preclude CPI-linked gilt issuance in the medium term, should there be a case to do so, it added.

(Reporting by Fiona Shaikh; Editing by Susan Fenton)