Developer Sean Mulryan's Ballymore International is to spend €500m redeveloping the Kudamm-Karree retail complex in Berlin.

The complex, which is "dilapidated and almost completely vacant", according to the company, was bought last year for more than €150m.

Ballymore International is owned by Mulryan and investors including FBD Holdings, Irish Public Bodies Mutual Insurances, Michael Smurfit and Brennan Holdings. The company was set up last year using €242m of debt and equity to fund its growth.

The company has already held talks with the local planning department and plans to include a 650-seat theatre as part of the scheme.

Paul Keogh of Ballymore said it could be on site by the middle of next year if planning is secured. He said the new theatre would cost €40m to construct.

"We are very relieved that finally an investor has taken responsibility for Kudamm-Karree who is also interested in the future of theatre activities," said Martin Woelffer whose family runs the existing theatre.

Ballymore is also planning to renovate an existing office building on the site and to construct a new three-level retail centre which would be modelled on its Eurovea scheme in Bratislava.

"Top brands have indicated that they would be interested in opening there," Keogh said, adding that it will also develop a restaurant and leisure area which would target upmarket, traditional German restaurateurs without a presence in the area.

Other assets owned by Ballymore International include the five-star Kempinski Hybernska in Prague which recently reopened after a €27m facelift and extension.