Granta is one of the great institutions of contemporary British literature. It has gone from modest beginnings in Cambridge to great things under two editors, Bill Buford and Ian Jack.

Buford established a pared-down voice as the mark of the magazine; he had a hand in establishing the careers of writers like Salman Rushdie, Paul Theroux and Redmond O'Hanlon, in the process single-handedly re-establishing travel writing as a live, commercially viable genre. Jack has built on Buford's achievement, bringing a new rigour and editorial steadiness, while always keeping an eye out for such astounding new talents as Chimamanda Ngozi Adichie.

I have reason to be grateful to Jack and his then deputy, Ursula Doyle, who edited the first chapter of what became The Last King of Scotland for the magazine. Doyle left to become one of Britain's premier publishing editors. Now Jack is going, too.

He will be a hard act to follow, as was Buford. Company MD David Graham, appointed by new owner Sigrid Rausing, is said to have been sounding out various candidates and has also advertised the post.

Jack's successor will be expected to find a new ethos and aesthetic for the magazine. My instinct is that it will demand a technical shift in fiction-writing, perhaps involving something to do with point of view; then the way will be open for writers to deal with the crises of cultural relativism and environmental collapse that are the pressing issues of our time.

But commercial considerations are also significant, and building Granta's circulation in the US, on lines established by the Economist and the TLS, would also be a good move.