The Dow Jones closed up for the third consecutive session on Thursday, adding 239.66 points (3.36%) to 7,170.06 (3.36%).
The FTSE 100 edged back into the black this morning after a week of tumultuous trading which saw the index drop sharply.
The FTSE 100's mid-week revival appears to be short-lived as the index fell again in early trading this morning, down 40.49 points, or 1.11%, to 3,605.38 at 8.45am.
US markets slid in early trading on Monday after AIG announced the largest ever corporate loss of over $60bn.
The FTSE 100 has dived below 3,700 this morning as the banking sector slides on HSBC's plans to raise £12.5bn from investors.
Despite turbulent mid-day trading, the FTSE100 built on early gains to rise 34.73 points (0.91%) to 3,851.17 shortly before 3pm.
Shares rose in London this morning after a late rally in New York helped push the Dow Jones up more than 200 points on Tuesday.
Royal Bank of Scotland has climbed more than 16% in early trading this morning after weekend reports suggested it could offload up to a quarter of its non-core businesses.
The Dow Jones fell to its lowest level in more than six years last night as some US banks plummeted.
The Dow Jones closed 297.81 points (3.79%) down last night at 7552.60 after news of further job cuts and government borrowing from Chrysler and General Motors (GM).