GlaxoSmithKline (GSK) has sold half of its 12.4% stake in Africa’s largest drug manufacturer, in the process raising ZAR 10.5 billion (about $842.7 million) for the pharma giant.

GSK sold some 28.2 million shares in Aspen Pharmacare through institutional investors, at ZAR 372 per share ($29.88). The selloff will leave GSK with 28.2 million shares in Aspen, representing about 6.2% of the company’s issued share capital.

GSK CFO Simon Dingemans said in a statement the deal will help the company by ensuring that shareholders continue to receive significant dividends, and by giving it capital at a time when it is restructuring its operations through an asset swap with Novartis.

On March 2, Novartis said it completed a series of previously-disclosed deals with GSK. The deals included acquiring the British pharma’s oncology business, and selling its non-influenza vaccine business to GSK. Also, both companies formed a joint venture for their consumer healthcare products, with GSK holding the majority 63.5% stake.

“As we continue to reshape the Group around our core franchises and drive the benefits from the Novartis transaction, optimizing our financial flexibility to invest behind these priorities is key. As a result we have decided now is the right time to realize further value from this successful relationship,” Dingemans said in the statement. “We continue to believe in the strategy of Aspen and we remain committed to working together in the future.”

GSK also agreed not to sell off any additional shares in Aspen for at least 180 days, except for undisclosed “limited exceptions.”

The shares just sold off by GSK were among shares bought by the pharma giant when it acquired a 16% stake in Aspen in 2009 for ZAR 3.47 billion (worth $410 million at the time). In return, GSK transferred to Aspen rights to market and distribute its drugs in South Africa, while the companies agreed to market and sell GSK products by combining commercial operations for current and future product portfolios in the rest of sub-Saharan Africa.

The companies also agreed that a nominee of GSK’s choice would join Aspen’s board. Aspen said its board will retain David Redfern, GSK’s chief strategy officer. He recently joined Aspen’s board as GSK nominee-director, succeeding Abbas Hussain, who is the pharma’s president, global pharmaceuticals.