REUTERS - Aug 23 - Two of eHarmony's main backers stand to gain extra leverage over the company when redemption rights from its last financing round kick in -- an unusual development in the venture capital business. The rights come into play after November 5 for Technology Crossover Ventures and Sequoia Capital, which invested when eHarmony raised $110M in 2004. The firms will have the right to require eHarmony to buy back their preferred shares in four quarterly installments.