Tullow Oil has shrugged off a temporary slip in the oil price to be second biggest gainer in a falling London market.
Tullow is up 2% to 906.5p at lunchtime, helped by Morgan Stanley raising its price target from £10.90p to £12.30p.
The vote of confidence in Tullow's prospects came as the US crude oil price fell to nearly $126 a barrel, extending last week's fall as traders took profits.
Mining companies are also among the top risers, buoyed by rising hopes that Rio Tinto and BHP Billiton can reach agreement on price hikes with China's steelmakers.
BHP Billiton is up around 1% at £19.27p and Rio Tinto has gained 32p at £60.86p.
In a quiet day for corporate news Bradford & Bingley's profit warning and revised rights issue has dragged down banking shares and the overall market.
The FTSE 100 is down nearly 60 points, or 1% at around 5995.
