If successful, the four year strategy would see Yell return to growth by 2015, with its emphasis on providing digital services to local markets.
The drop wiped out gains made by Yell in the wake of an announced tie-up with Microsoft.
The Yellow Pages publisher also said its guidance for its full year results were unchanged and current trading is in line with expectations.
Shares in Yell closed down 23.64 per cent at 8.4p.
Yell, which narrowly avoided insolvency in 2009 and had net debt of £2.83bn at 31 March, is exploring options for its debt pile and has already been talking to its major lenders.
Earlier this week Yell agreed to buy US technology start-up Znode for $20m (£12.5m), pushing its shares up nine per cent.
The firm says Znode gives Yell e-commerce technology that it can use to connect small businesses with consumers on a local level. It will be incorporated into the group as part of a new division, called Yell Connect.