Week in pictures: November 9

Chuck Prince, Citigroup
Total remuneration: £77.5m (since 1999 or during length of service)
Bank market capitalisation (August 2007): £114.8bn
Bank market capitalisation (now): £13.0bn
Credit crunch hits (since August 2007): £140.6bn
Photograph: Yoshiko Kusano/EPA

Democratic presidential candidate Barack Obama has written to Tesco chief executive Sir Terry Leahy to urge the UK grocer to start talks with a US trade union over workers' rights at its new California-based business Photograph: David McNew/Getty

The world's largest mining group, BHP Billiton, is seeking to take over its rival Rio Tinto in a deal that would catapult it to a market valuation of about $360bn (£170bn), bigger than Microsoft and equivalent to the gross domestic product of Ukraine. Read the article Photograph: AP

The auction house Sotheby's suffered an almost 40% slump in its share price yesterday in the wake of a disappointing sale of Impressionist and modern art, prompting speculation that the art market bubble is starting to burst. Vincent van Gogh's landscape, Wheat Fields, possibly his last finished work, painted in 1890 two weeks before he committed suicide, was left unsold. Read the article Photograph: EPA

PetroChina became the world's first trillion-dollar company after shares in the business almost tripled in value on its flotation on the Shanghai stock market. Pictured is the company's chairman, Jiang Jiemin. Read the article Photograph: Mike Clarke/Getty

Marks & Spencer has announced a new push into India and China on the back of better-than-expected results for the last six months. Read the article Photograph: PR

The oil price will shoot back through $100 a barrel as soon as economic conditions return to normal, and will break through $200 threshold by 2030, say officials at the International Energy Agency Photograph: Pablo Krisch/AP

Britain's car dealers are facing their toughest trading conditions for many years in the face of economic uncertainty, slumping consumer confidence and ever decreasing disposable income, according to a new report. Read the article Photograph: Sascha Schuermann/Getty

The Bank of England, headed by governor Mervyn King, has been lobbied by high street banks to extend the special liquidity scheme, put in place this spring to help free up money markets which have been frozen by the credit crunch. The Bank said the scheme was going according to plan and some of the urgency had diminished in terms of banks needing to access it. Read the article Photograph: Bruno Vincent/Getty

Global banana companies supplying the UK, such as Chiquita, are using tax havens to avoid paying tax on their profits here and in developing countries. Read the article Photograph: Kent Gilbert/AP

Bagless vacuum cleaner pioneer Sir James Dyson picked up a £59m salary and dividend payout after seeing profits soar by nearly a fifth. Read the article Photograph: Stefan Rousseau/PA