The FTSE 100 is up 23.2 points, or 0.39%, to 5.923.6, as Saudi Arabia has agreed to buy a number of fighter jets from BAE Systems.
BAE Systems, Europe's biggest weapons company, has gained 2.85% to 370.25p after it agreed to supply Saudi Arabia, the largest economy in the Middle East, with 72 Eurofighter Typhoon jets in a deal which could be worth £6bn.
Imperial Tobacco, Europe's second-largest cigarette maker, has advanced 1.8% to £18.1p, while British American Tobacco has gained 1.24% to £14.64, after a US Court found cigarette makers liable for violating racketeering laws but did not inflict any major financial penalties on the industry.
Elsewhere, PartyGaming, despite a good day yesterday, has fallen 2.2% to 111p, after analysts cut its rating to "hold", with dollar weakness cited as one factor in the move, along with increased industry risk.
In Japan earlier today, the Nikkei 225 Stock Average advanced 85.14, or 0.5%, to 16,105.98, as crude oil prices fell to a two-month low, easing concern fuel costs will curb spending and growth in the US, Japan's largest overseas market.
Exporters such as Sony and Bridgestone led the gains with Sony, the world's No. 2 consumer electronics maker, up 140 yen, or 2.7%, to 5,310, while Bridgestone climbed 50 yen, or 2.2%, to 2,370, and Matsushita Electric Industrial, the maker of Panasonic-brand products, rose 25 yen, or 1%, to 2,485.
Other companies dependent on oil also advanced on the price drop, with Mitsubishi Logistics, which provides trucking and international shipping services, surging 67 yen, or 3.8%, to 1834, while Tokyo Electric Power, the nation's biggest utility,, rose 70 yen, or 2.2%, to 3,220.
However, energy-related companies were the biggest drag on the index, as Inpex Holdings, Japan's biggest oil explorer, dropped 10,000 yen, or 0.9%, to 1.04 million, while Japan Petroleum Exploration, the country's second biggest, slid 230 yen, or 2.8%, to 8,020.
In the US, the Dow Jones Industrial Average closed slightly higher with gains of 7.84 points, or 0.07%, to 11,334.96, as a sharp drop in oil prices spurred buying in industrial shares.
In addition, crude oil delivery for September fell nearly $2 a barrel to just over $70, to lift shares of industrial companies with a big appetite for energy, such as General Electric, which rose 0.6%, or $0.21, to $33.92.
But shares of the drug company Merck fell 5.7%, or $2.35, to $38.83 to act as the biggest drag on the Dow, after the company suffered a double setback when a federal jury awarded $51m to a former user of its withdrawn pain medicine Vioxx, and a New Jersey judge threw out a Vioxx verdict which had favoured Merck, citing new evidence.
However, Hewlett Packard provided some good news as it rose 2.1%, or $0.72, to $35.15 to become the top gainer, after it announced in its quarterly report it had beaten profit estimates and is planning a $6bn share buyback scheme.
And tobacco stocks, including shares of Altria Group, the parent of cigarette maker Philip Morris USA, rose in late trading after the bell, to reverse earlier declines, after a federal judge issued a ruling which sided with the government, but did not impose fines.
Altria gained 3% to $83.20 after US District Judge Gladys Kessler found the government had proved its case which accused cigarette makers of a decade-long conspiracy to hide the dangers of smoking. But she said a previous ruling by an appeals court prevented her from ordering the companies to pay monetary penalties.IFAonline
Two global vehicles
'Further plug advice gap'
Must appoint separate CEOs and boards
Advisers do come out well
Will report to Mark Till