By Lars Mucklejohn Insurance giant Aviva has posted a rise in annual profits as it rewards shareholders with a £300m buyback and upgraded dividend guidance. The FTSE 100 firm reported an operating profit of £1.47bn for 2023, up nine per cent from £1.35bn in 2022. This figure was a slight beat on analysts’ estimates. General insurance premiums rose 13 per cent to £10.89bn, driven by strong performances in Canada and the UK. Aviva’s workplace pensions business saw a record £6.9bn of net flows as it won 477 new schemes last year. The insurance giant’s private health business saw a 41 per cent boo…