In mid-morning trading, the index was up more than 2% at 6,113.03, while theFTSE 250 had gained 2.6%.
The FTSE 100 lost 5.6% in the previous two trading sessions, while the more UK-focused FTSE 250 had slumped 13.7%.
The pound also showed signs of recovery, rising 0.6% against the dollar to $1.3307.
