Aviva PLC.

The deal, if approved by shareholders and regulators, would create Britain’s largest life insurer, worth roughly £20.7 billion and with more than £300 billion in assets under management.

The British insurer said late on Friday that it had a preliminary agreement to acquire Friends Life Group in an all-share deal worth about $8.8 billion that would create Britain’s largest life insurer.

Robin Spencer will be head of international insurance for the NN Group, succeeding David Knibbe, who will become chief of the group’s Dutch insurance business.

The offering represents the final dismantling of Acromas, which was created in 2007 by the merger of the AA and Saga, a seller of travel and insurance packages targeting the over-50 crowd. The AA’s shares fell 4 percent after the offering.

The British insurer said its asset management arm would sell River Road Asset Management, the Kentucky-based institutional investment management firm, to Affiliated Managers Group for an undisclosed amount.

The latest UK budget ushers in pension reforms which will potentially free up billions of pounds for investment. Joanna Partridge looks at what impact it will have on the pensions industry.

A unit of Apollo Global Management agreed on Friday to buy the American operations of Aviva, the British insurer, for about $1.55 billion in cash.

Andrew Moss, the chief executive of the British insurance company Aviva, resigned unexpectedly on Tuesday as a result of shareholder discontent over pay practices.

UBS is among a growing number of companies to come under pressure from shareholders for handing out large pay packages while their earnings — and share prices — decline.

Aviva joins numerous other companies that have faced investor criticism recently about how much top executives are paid relative to shareholder returns and the overall performance of the firm.