Talen Energy gains on 2027 outlook, expanded share buyback plan

** Shares of power producer Talen Energy TLN.O up 3.6% at $344.9 premarket

** Introduces 2027 adjusted EBITDA guidance of $2.5 bln-$2.85 bln

** Says 2027 EBITDA guidance implies about 26% growth at the midpoint versus 2026 guidance

** Announces $1.5 bln accelerated share repurchase program and upsizes share repurchase authorization to $3 bln through 2028

** Reaffirms 2026 adjusted EBITDA guidance of $2.05 bln-$2.2 bln

** Reports Q3 adjusted EBITDA of $669 mln, up from $363 mln a year earlier

** Up to last close, TLN down 11.2% YTD