Saw producer of Marmite tip gas freely (13)

I believe the answer is:

epigrammatist

'saw producer' is the definition.
(saw can mean a saying or epigram)

'marmite tip gas freely' is the wordplay.
'freely' indicates anagramming the letters.
'marmite'+'tip'+'gas'='marmitetipgas'
'marmitetipgas' anagrammed gives 'EPIGRAMMATIST'.

'of' is the link.

I've seen this clue in The Times.

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