(Corrects 'firm' to 'offer' in first paragraph)
LONDON, July 1 (Reuters) - The Amsterdam float of ING'S insurance arm NN Group is likely to price at 20 euros a share, three sources familiar with the deal said on Tuesday, valuing the offer at 1.54 billion euros ($2.10 billion).
Reuters reported on Monday that orders below 20 euros were likely to miss out. The original price range was set at 18.50-22 euros, later narrowed to 19.50-20.50 euros.
Earlier on Tuesday ING said it was raising the offer size to 77 million shares from 70 million in response to strong demand.
$1 = 0.7331 Euros Reporting by Freya Berry; Editing by Mark Trevelyan