ZURICH, Nov 5 (Reuters) - Roche said on Friday that its controlling family will be exempt from having to make an offer to other shareholders after the drugmaker’s $20.7 billion deal to buy back Novartis’s nearly one third voting stake. The pool of family shareholders, who previously owned 45.01% of the voting rights in Roche, were given the exemption by the Swiss takeover board, the company said. The decision was confirmed on the takeover board’s website. In Switzerland a mandatory offer obligation is normally triggered whenever a shareholder or group of shareholders directly or indirectly acquires equity securities in a listed Swiss company that exceed 33.33% of the voting rights. Roche said on Thursday, when the Novartis deal was announced, that it will use debt to finance what it called a “disentanglement of two competitors” and plans to reduce its capital by cancelling the repurchased shares to regain full strategic flexibility. (Reporting by John Revill; Editing by Susan Fenton)