Pensions heavyweights Just Retirement and Partnership Assurance have received approval for their £1.6bn merger from financial regulators.
Both the Financial Conduct Authority and the Prudential Regulation Authority have given approval to the all-share merger, which was agreed in August last year.
Plans to merge the annuities companies came in the wake of pension reforms announced in March 2014, after George Osborne's liberalisation of pension laws caused sales of annuities to drop.
In May last year Just Retirement announced its sales had fallen 22 per cent over nine months, as the effects of the pensions changes meant people beginning their retirement no longer needed to buy an interest-bearing annuity with their pension savings.
Just Retirement and Partnership Assurance said further details will follow when they announce results on Friday.
Changes to pensions in the 2016 Budget such as a pensions Isa, relief rates being slashed for higher earners and the scrapping of the current salary sacrifice scheme, are among the measures many think Osborne might introduce next week.
In February the former pensions minister Steve Webb said a pensions Isa would amount to committing "daylight robbery".