Transaction in Own Shares

BP PLC
21 September 2005

BP p.l.c.  -  Transaction in Own Shares
BP p.l.c.  -  21 September 2005

BP p.l.c. announces that on 20 September 2005, it purchased 10,290,000 ordinary
shares at prices between 660.50 pence and 675.00 pence per share and between
1187.50 cents and 1198.33 cents per share. The purchased shares will all be held
as Treasury shares.

Following the above purchase, BP p.l.c. holds 598,883,081 ordinary shares in
Treasury, and has 20,923,295,757 ordinary shares in issue (excluding Treasury
shares).

Enquiries: Fergus MacLeod, BP p.l.c.    Tel : [phone]


                      This information is provided by RNS
            The company news service from the London Stock Exchange