ART

The British government has stepped up its attempts to acquire the art collection of Baron Thyssen-Bornemisza, with Prime Minister Margaret Thatcher herself entering the fray, officials said on Monday. The government’s bid for the collection, rated in the art world as second in importance only to that of Queen Elizabeth, was approved by the Cabinet and forwarded to the baron with a handwritten letter from Thatcher, Thatcher aides said. The baron, a 67-year-old Swiss industrialist, has been seeking a permanent home for the bulk of his collection--estimated to be worth more than $1.4 billion--and has sparked off a fierce struggle between Britain, Spain and West Germany for the honor.