The paintings were created during Lowry's time in the region

The paintings, which were created in the 1960s when the artist lived in the region, have been on display at Sunderland Museum and Winter Gardens.

They could have been sold at auction, which would have meant them being removed from display at the museum.

But they were thought so important, the Treasury allowed a private treaty sale to stop them going to private buyers.

The paintings - Dockside, The Sea at Sunderland and Self Portrait I - were bought with a �175,000 grant from the Heritage Lottery Fund.

The works were painted during the 1960s

Funding of �15,000 also came from the Museums, Libraries and Archives Council and Victoria & Albert Museum Purchase Grant Fund, �7,000 from Sunderland Museums Acquisitions Fund and �3,000 from the Friends of Sunderland Museums.

The former owner was keen that the paintings should stay together at the museum and has arranged to bequeath a fourth painting, Self Portrait II.

Regional manager for the Heritage Lottery Fund (HLF) in the North East, Keith Bartlett, said: "HLF is proud to play a part in ensuring that this local heritage is retained in the region and will be accessible to everyone."

Museum curator Juliet Horsley said she was "thrilled" they had been able to secure the purchase of the paintings.

She said: "These new acquisitions complement the industrial landscapes and mill scenes, set in the Manchester/Salford area that established his reputation.

"They are important examples of another major aspect of his artistic output - the work he produced as a result of the time he spent in the North East of England."