As news emerged on Tuesday that Zurich was weighing up the acquisition, RSA’s share price soared by more than 18% to 518.5p at the close.
Zurich must make a decision on whether to make an offer before 5pm on 25 August.
RSA said it has not held talks with the Swiss insurer or received a proposal from the firm. Shareholders have also been advised to “take no action”.
Tuesday’s announcement saw Zurich shares fall by 1.8%.
Meanwhile, at the open on Wednesday, the RSA share price rose to a high of 520p before plummeting to a low of 503.1p at around 8.10am GMT. It then recovered, climbing by 2.6% since today’s open to 505p (10.50am GMT).
Solely in cash
Media reports indicate that the bid is likely to be solely in cash.
Since the start of the year, RSA has sold various arms of its business, including its China insurer Sun Alliance, and its Singapore and Hong Kong operations.
Today the London-headquartered business also announced it had completed the sale of its stake in joint venture, India-based Sundaram Finance.
The London insurer said it was looking to focus on its core assets in the UK, Ireland, Scandinavia, Canada and Latin America.
