Most of the population of the developed world will be within driving distance of a Lego theme park under a plan by the Danish toy company to build 15 new parks next century.

The parks are part of a plan by the privately owned Lego, Europe's biggest toymaker and among the world's biggest seven toy companies, to increase sales by pushing its brand name deeper into a range of other activities.Disclosure of the plans, estimated to cost $2 billion, follows an announcement last month that the company is forming an alliance with Mindscape, a U.S. software company owned by Pearson, publisher of the Financial Times, to develop interactive compact disc software systems featuring Lego play activities. The first of these products is due to be unveiled later this year.

Lego is examining sites on the U.S. East Coast, eastern Asia and southern Europe for the chain of 15 parks, which would be built by around 2050.

They would follow the company's existing Legoland theme park at its headquarters in Billund, Denmark. A second one is due to open in Windsor, England, later this month and a third is planned to open near San Diego, Calif., in 1999.

The sites should cost roughly $138 million each to develop.

"We look at this the theme parks project as a very interesting business," Kjeld Kirk Kristiansen, Lego's president and majority stakeholder, said Tuesday.

"There is a lot of synergy between people getting the best possible experience from our theme parks and being inspired to buy our products," he said.

Lego, which has nearly 9,000 employees in 26 countries, does not reveal its annual sales, but these are estimated in the toy industry at about $1.4 billion.

The company is estimated to have made more than 100 billion plastic bricks and other units such as miniature pirates, parrots and spacemen since 1932.