The Cuban artist's posters will also be displayed throughout central Cardiff, while visitors to the exhibition at the National Museum of Art will be invited to sign a 'moral commitment contract' promoting immigrants' rights.

BBC: Artes Mundi 5: Exhibition and prize open in Cardiff

Faced with persistent speculation about his future as boss of Siemens, Mr Kleinfeld told the 20-strong board before their gathering that he would leave the company if they did not make a firm commitment to renew his contract.

ECONOMIST: German business

The site says the pledge is a "moral commitment" not a "legal contract".

BBC: US billionaires pledge 50% of their wealth to charity

The pledge is a moral commitment to give, not a legal contract, and it does not involve pooling money or supporting a particular set of causes or organizations.

FORBES: Ten More Tycoons Sign Buffett And Gates Giving Pledge: Dalio, Kinder, DeJoria

Meanwhile, 18-year-old defender Sam Hutchinson has signed a new four-year contract at Stamford Bridge, following Scott Sinclair's commitment to a long-term deal last week.

BBC: SPORT | Football | My Club | Chelsea | Makelele extends Chelsea contract

Roby's future was the subject of much speculation during the 2010 Four Nations in Australia and New Zealand but the England international recently made his commitment to St Helens clear by penning a new three-year contract.

BBC: James Roby craves Grand Final medal with St Helens

Should the contract expire worthless, the premium would represent a 6.67% return on the cash commitment, or 39.89% annualized at Stock Options Channel we call this the YieldBoost.

FORBES: MHR July Options Begin Trading

Should the contract expire worthless, the premium would represent a 2.50% return on the cash commitment, or 14.96% annualized at Stock Options Channel we call this the YieldBoost.

FORBES: SVM July Options Begin Trading