By Jemima Denham and George Abbott

April 2 (Reuters) - Three paintings by French masters Pierre-Auguste Renoir, Paul Cézanne and Henri Matisse stolen from ‌a museum in northern Italy last week were probably not ‌insured, according to market sources.

One fine art underwriter told the Reuters publication The Insurer that ​the paintings, estimated to be worth around $10 million, had previously failed to secure insurance cover due to the cost.

The heist reportedly took only three minutes from the moment the thieves forced their way in through the main ‌entrance of the Fondazione ⁠Magnani Rocca, near Parma, on the night of March 22.

They stole Cézanne’s “Tasse et Plat de Cerises” (Cup and Plate of ⁠Cherries), Renoir’s “Les Poissons” (The Fish) and Matisse’s “Odalisque sur la Terrasse” (Odalisque on the Terrace), police said.

One source said they had been surprised at the thieves' choice of ​works of ​relatively low value from the museum’s ​permanent collections, which also contain ‌artworks by the likes of Monet, Durer and Rubens.

The lack of commercial insurance for paintings like the stolen ones is not uncommon, market sources say.

In a high-profile heist last October, thieves took 88 million euros' ($101 million) worth of crown jewels from the Louvre Museum in Paris.

As in Italy, ‌the government was expected to indemnify the ​museum as no commercial policy was in ​place for the jewels, a ​part of the permanent collection.

Most losses occur when works ‌are being transported for storage or ​temporary exhibitions, and this ​tends to be the focus of commercial art insurance.

For permanent collections, the cost to individual museums or galleries of insuring against ​the substantial risk of ‌theft or damage is prohibitive. For museums or heritage sites of ​national standing, the state often acts as a de facto ​insurer.($1 = 0.8678 euros)

(Editing by Kevin Liffey)