* Says will pay additional $5.5 million to Pancontinental upon spud of first exploration well
* Africa Energy acquires interest in Namibia
* Says announces acquisition of one-third of shares in unit of Pancontinental Oil & Gas N.L.
* Says Africa Energy paid Pancontinental US$2.2 million at closing
* Says partnered with Pancontinental for an effective 10 percent interest in PEL 37 offshore Namibia Source text for Eikon: Further company coverage: