Spanish oil and gas firm Repsol is to buy Canadian shale-focused group Talisman Energy in an agreed takeover worth nearly $13bn.

Repsol will pay $8.3bn for all the shares in Talisman and will assume $4.7bn in debt. Talisman is a shale-focused firm with half of its 280,000-290,000 barrels of oil equivalent per day (boe/d) production in 2014 sourced from its North American operations.

The deal will see Repsol pay $8 per share in cash, an eye-watering 103% premium to...