LONDON, Nov 26 (Reuters) - Investors scaled back their bets on Friday on the chance of a Bank of England interest rate hike in December after a coronavirus variant that might be harder to combat with vaccines was detected in South Africa. Interest rate futures were pricing a roughly 55% chance of a 15 basis-point rate hike by the BoE on Dec. 16 - after its next scheduled monetary policy meeting - compared with a roughly 75% chance on Thursday. The BoE"s new chief economist, Huw Pill, said he thought the way was clear for a first rise in rates since the start of the coronavirus pandemic. But he declined to send any signal about the likelihood of a move as soon as next month and he said there were still risks to public health. read more Yields on 10-year British government bonds tumbled by 15 basis points, their biggest one-day fall since the onset of the financial crisis in March 2020, mirroring moves in U.S. Treasuries and other government bonds.