As the unrest escalates in Iraq, with Islamic insurgents reportedly attacking the country's largest refinery, oil companies were boosted by the continuing strength of the crude price.
Royal Dutch Shell B shares rose 44p to £25.33 with analysts also taking a positive view of the company's plans to sell the bulk of its stake in Australia'sWoodside Petroleum for $5.7bn and to float part of its pipeline assets.
Elsewhere BP put on 8.3p to 514.4p and BG was 7p better at £12.67.
Mining shares were also supported by the crude price - Brent held firm at around $113 a barrel - and by pledges from China to boost economic growth. Rio Tinto rose 30.5p to 3079.5p, while BHP Billiton was 22p better at 1874.5p.
Genel Energy, which operates in Kurdistan, added 14p to 537.5p despite Oriel Securities issuing a downbeat note on the business:
At the current price, we see little implied risk of accident, disappointment, failure or miscalculation in regard to the business of producing and selling oil in Kurdistan. As such, we do not think the 'political de-risking' buy case for Genel is compelling.
Given this view, we think only a speedy maturation of the gas development portfolio, coupled with exploration success in Angola or Morocco, can support the current share price. Our negative stance on these key assets leads us to a reduce recommendation.
One compelling reason to hold Genel is the potential for a corporate takeover at a higher price level. The strategic significance of Tawke and Taq Taq make them appealing to an acquirer, especially should the Kurdistan Regional Government move further towards autonomy and/or independence in the months ahead. However, given recent violence, political disquiet and Genel's $4bn enterprise value, we think an outright sale is unlikely for some time.
Overall - after the Bank of England minutes, which showed a 9 nil vote for no change, and ahead of the US Federal Reserve's latest decision, widely expected to see another $10bn cut in its monthly bond buying programme - the FTSE 100 finished 11.79 points higher at 6778.56. Alastair McCaig, market analyst at IG, said:
Investors are braced for a potentially hawkish statement [on interest rates] from the Federal Reserve, having had the Bank of England minutes this morning as a warm-up act. The gains made today on the FTSE have been founded on energy firms, which at the moment are benefiting from higher oil prices. Despite this, traders are keeping one eye on the Iraq situation at all times, with the uncomfortable knowledge that higher oil prices will not be beneficial for the global economy.
Shire gained more ground on takeover speculation, with US analysts suggesting the pharmaceuticals group could be a good fit for Allergan, itself a bid target.
On Tuesday Shire rose more than 3% on reports it had hired Citigroup as an advisor because it expected an approach. Now analysts at SunTrust have issued a note saying Shire could be a target for US group Allergan, which is fighting off an unwanted approach from rival Valeant. Shire closed 125p or 3.4% higher at £37.85.
Vodafone climbed 2.85p to 198.1p after India's former supreme court chief justice R.C. Laholi was appointed as arbitrator in the company's tax dispute with the government. Communications minister Ravi Shankar Prasad said the government would try and resolve its rows with telecoms companies.
But United Utilities lost 24.5p to 861.5p and Severn Trentwas down 41p at £19.28 as both water companies saw their shares go ex-dividend.
IMI fell 38p to £15.26 as RBC cut its rating on the engineering group from outperform to sector perform.
The housing market was in focus, with Berkeley down 23p at £22.38 on profit taking after it reported a 40.4% rise in full year profits and issued a confident update. Barratt Developments dropped 3.6p to 345.4p in sympathy.
Property website Zoopla climbed to 230p in conditional trading after pricing its shares at 220p each.
Elsewhere SuperGroup, the fashion retailer behind the Superdry brand, recovered 16.5p to 870p after its recent slump. Investec analyst Kate Calvert issued a buy note, saying:
SuperGroup's shares are off 39% since the fourth quarter's weak sales update and have been de-rated from 18.6 times 2015 earnings to 11.3 times on our numbers. This seems excessive for a less than 2% cut in consensus earnings and to us implies the market is expecting a profit warning. While we do not see the first quarter interim management statement on 4 September as a catalyst, we do expect 2014 results (10 July) to reassure on the brand's longer term growth potential and opportunity to leverage its infrastructure.
Outsourcing group Serco, where Rupert Soames recently became chief executive, slipped 0.5p to 360p. Soames has been quick to make his mark, announcing a split with its rail joint venture partner Abellio and restructuring its troubled Africa, Middle East, Asia and Australasia division. In a hold note Liberum said:
Serco will split from Abellio when bidding for Northern (where they are incumbent) and TransPennine Express. This increases the re-bid risk on Northern, Serco's second largest contract after Australia'sDepartment of Immigration and Citizenship, which is likely to be decided the second half 2015.
In addition AMEAA is being restructured, and it will report directly to Rupert Soames and [chief operation officer] Ed Casey. Separately, we understand that Serco will issue a pre-close in early July, not have the habitual half yearly analyst meetings and issue interims on 12 August. The shares have responded positively to the appointment of Rupert Soames and have moved ahead of our 350p target price. However, a 2015 PE of 20.0 times seems to provide limited discount for the potential for further earnings weakness, the issue of new paper or dilution from disposals. Serco has taken a long time to go wrong and will take a long time to fix.
Inkjet specialist Xaar continued to slump after Tuesday's warning, down another 37p or nearly 7% to 500p.
Finally Aim-listed Corero Network Security, a provider of security solutions for defending against DDoS attacks and cyber threats, rose 2.5p to 25p after announcing its largest ever order for its novel First Line of Defence solution, valued at half a million dollars for a leading Wall Street financial services firm.