Six Lowry paintings are expected to fetch a combined total of £3m when they go under the hammer.
Good Friday, Daisy Nook is expected to fetch about £1.5m
The pictures will be auctioned during British Art Week and auctioneers said the sale is set to be the highlight.
One of the works - Good Friday, Daisy Nook - was last sold in 1970 for a then-record £16,800.
The record price for a Lowry was the £1.9m paid by the Professional Footballers Association (PFA) for Going To The Match in 1999.
Lowry only painted in his spare time as he worked with the Pall Mall Property company in Manchester until his retirement in 1952.
He was made the official artist at the coronation of the Queen in 1953, but he later turned down a knighthood.
Good Friday, Daisy Nook, which portrays the Lancashire town in post-war festival mood, is now estimated to fetch £1.5m at auction-house Christie's.
Christie's said the sale is the finest and most comprehensive private collection of paintings by the artist to appear at auction.
The paintings are being sold by a private collector
Other works in the collection include The Mansion, Pendlebury - set in Lowry's home town - which is expected to take £250,000 to £350,000.
The northern industrial townscape depicted in Factories, Lancashire is expected to go for between £500,000 and £800,000.
Other works being sold by the private anonymous buyer include Beach and Promenade, Whitehaven, and Footbridge, South Shields.
The London sale takes place at Christie's British Art Week in June.