Shares in BP were up today on the FTSE 100 after the company successfully ended the flow of oil from a broken well into the Gulf of Mexico.

BP is currently testing a new cap designed to stop the flow of oil. The energy giant is specifically concerned about whether the cap can withstand the high levels of pressure it is experiencing so deep under water and with such huge volumes of oil involved. So far BP has warned against pre-mature celebration.

U.S. President Barack Obama, who has been extremely critical of BP since the leak began April, said the news was a "positive sign".

Even if the cap is fully successful then a massive clean-up operation still needs to be undertaken. U.S. authorities are currently examining the possibility of using chemicals to disperse the spilled oil.

By 14:12 shares in BP were up 3.95 per cent on the FTSE 100 to 417.60 pence per share.