ACCRA, July 18 (Reuters) - The Bank of Ghana said the yield on its 91-day bill rose to a fresh three-year high of 24.8385 percent at Friday's auction, from 24.3109 percent at the last sale.

HAMBURG, July 18 (Reuters) - Trade in Europe's cash cocoa market remained restrained this week as industry hoped cocoa futures will continue their drift down from around three-year highs touched in early July, traders said on Friday.

PRETORIA (Reuters) - South Africa launched a set of limited edition gold and silver coins on Friday to honour former president Nelson Mandela on what would have been the late anti-apartheid hero's 96th birthday.

MELBOURNE/AMSTERDAM (Reuters) - The world of AIDS research was in shock on Friday after dozens of leading HIV experts were feared killed when a Malaysian plane was shot down over Ukraine, fuelling concerns that research on curing the disease could suffer.

YAOUNDE, July 18 (Reuters) - Cameroon's local cocoa grinders purchased 32,042 tonnes of beans for grinding by the end of June, up from 30,496 tonnes in the same period in the 2012/13 season, according to statistics from the National Cocoa and Coffee Board (NCCB) seen on Friday.

KHARTOUM (Reuters) - The family of a Sudanese woman who was spared a death sentence for marrying a Christian South-Sudanese American has filed a lawsuit to have her marriage annulled in a new attempt to stop her leaving the country.

DAKAR/ABIDJAN (Reuters) - An armed Islamist group formed by al Qaeda commander Mokhtar Belmokhtar claimed responsibility on Thursday for a suicide bombing this week that killed a French soldier in northern Mali.

TUNIS (Reuters) - At least 14 Tunisian soldiers were killed when dozens of gunmen with rocket-propelled grenades attacked two checkpoints in the remote Chaambi mountains, one of the deadliest militant strikes on the north African country's armed forces.

TRIPOLI (Reuters) - A Libyan militia battling a rival armed group over control of the country's biggest airport is ready for a peaceful solution after five days of heavy fighting, a spokesman said on Thursday, hours after shells hit the terminal building.

The following company announcements, scheduled economic indicators, debt and currency market moves and political events may affect African markets on Friday. - - - - - EVENTS: ANGOLA - Expecting the latest inflation data. GLOBAL MARKETS Asian shares sagged and a drop in Treasury yields pressured the dollar on Friday after news of a downed Malaysian airlines jet at the Ukraine-Russia border sent investors scurrying into defensive assets. WORLD OIL PRICES Brent future