Thyssen museum shows off masterpieces for first time in £30m extension

One of Madrid's leading art galleries - the Thyssen Bornemisza Museum - has doubled in size with the opening yesterday of a stunning extension to house paintings belonging to Baroness Carmen Thyssen Bornemisza, widow of the museum's founder.

One of Madrid's leading art galleries - the Thyssen Bornemisza Museum - has doubled in size with the opening yesterday of a stunning extension to house paintings belonging to Baroness Carmen Thyssen Bornemisza, widow of the museum's founder.

The new annexe, covering 8,000 square metres, was created from two mansions next to the former Villahermosa palace from which the existing museum was converted 11 years ago. Around a thousand paintings are now on show.

Among the 300 paintings exhibited in Madrid for the first time yesterday are works by Monet, Renoir, Gauguin and Picasso, plus works by 17th-century Dutch painters and 19th- and 20th-century Spanish, British and American painters. Pride of place goes to John Constable's The Lock.

The Spanish state paid €44m (£30m) for the extension, whose design and construction was masterminded by the innovative Catalan architects, Manuel Baquero and Francesc Pla. The investment is an act of faith by Spain - the collection remains the baroness's private property.

The new building, which forms an L-shape with the old, will house the baroness's collection for 11 years. No one wants to speculate about what might happen then. "There's lots of time to answer that question," said Tomas Llorens, the museum's director. "The natural thing would be for the two collections to stay together in this same museum. We plan shortly to fuse the collections and present them jointly in a permanent way."

The baroness said she was especially fond of Gauguin's Mata Muha, the last work the artist painted in Tahiti, which she bought in 1982 "because that was the moment when I knew I was going to be an art collector."

Carmen Thyssen, a former Spanish beauty queen turned one of the world's most avid collectors, said she was still adding to the collection she started 22 years ago for her personal enjoyment. She was acquiring late 20th-century works, but discreetly: "I don't want to give names."

Her collection strengthens the main themes of the museum, especially Impressionism, post-Impressionism and expressionism, which are poorly represented in other Spanish museums.

A temporary exhibition of her collection of Catalan art from the 1850s to the 1930s will stay in the gallery until mid-July before travelling the world. An exhibition of Andaluz works of the same period is promised soon. "If I hadn't bought these works many would have been lost," the baroness said.

"We don't value our 19th-century Spanish artists. If they'd have been French they'd have been hailed as comparable to Monet or Van Gogh." Later this month, the Reina Sofia Contemporary Art Museum, which is just down the road, launches its new extension with a blockbuster Lichtenstein exhibition.