By Huw Jones and Carolyn Cohn

Aviva named independent director and former Zurich Insurance executive Amanda Blanc as its new chief executive on Monday who immediately signalled a potential strategy overhaul, sending the British insurer's shares up.

Blanc succeeds Maurice Tulloch whom Aviva said was stepping down with immediate effect for family health reasons. It is the second change at the top in less than two months after chairman George Culmer took up the reins in May.

The changes have revived speculation of a break-up of the life and general insurer, which some analysts and investors say has an unwieldy structure.

"I'm not a business as usual person, and I haven't come here to do a business as usual job," Blanc, the first woman to run Aviva, said on a media call.

"We will look at the strategic options."

Aviva's shares hit a three-week high and were up 4% at 1314 GMT, outperforming a 1.7% rise in the FTSE 100.

Insider Tulloch took the top role in March, 2019, amid concern about Aviva's lagging stock market performance.

KBW analysts said they expected Blanc's appointment to lead to a strategic review, less than a year after Aviva reorganised into five divisions.

KBW advocated a break-up of the group "as the best way to maximise value".

Blanc was appointed in January to the board of Aviva, which traces its history to the launch of the Hand in Hand Fire & Life Insurance Society in London in 1696 and has businesses in Europe, Asia and Canada.

Prior to Zurich Insurance, Blanc was group CEO, AXA, and has served as chair of the Association of British Insurers and president of the Chartered Insurance Institute.

"The board and I were saddened to hear of the personal reasons behind (Tulloch's) desire to step down and we wish him and his family the very best for the future," Culmer said.

(Additional reporting by Muvija M in Bengaluru and Ritvik Carvalho in London; editing by Patrick Graham, Jason Neely and Emelia Sithole-Matarise)