LONDON, May 18 (Reuters) - British energy suppliers Centrica and SSE rose on Thursday, extending gains after the UK Conservative Party's manifesto pledge to cap household energy tariffs soothed investors' worries about the severity of the caps.
Centrica rose 4 percent, while SSE gained 1.8 percent. Both had been hit earlier in the month when Prime Minister Theresa May's Conservative Party said that they would cap domestic prices if they won a general election in June.
Analysts at Jefferies and Bernstein both said that the hit to the companies from the proposed price cap might not be as great as initially feared. (Reporting by Kit Rees and Helen Reid, Editing by Vikram Subhedar)