LONDON, April 23 (Reuters) - British engineering company Rolls-Royce said it was in constructive talks with Spain over the sale of its Spanish unit ITP Aero, after a media report said Madrid could block the deal. Rolls-Royce is hoping to secure up to 1.5 billion euros ($1.8 billion) from the sale of turbine blade-maker ITP Aero, which it has put on the block as part of a 2-billion-pound ($2.8 billion) asset sale to help repair its balance sheet after the pandemic. Bloomberg reported earlier on Friday that the disposal could be blocked by Spain unless the buyer could offer reassurances about ITP’s future, citing a person familiar with the matter. Rolls-Royce said the relevant Spanish authorities - ITP is headquartered in the Basque region of Spain - were involved in the process and talks were positive. “The Spanish and Basque governments are important stakeholders and there is an ongoing and constructive dialogue with them,” a Rolls-Royce spokesman said in an emailed statement. Rolls-Royce said there were multiple interested parties in the sale process, adding that ITP would also continue to be a supplier to Rolls-Royce for many decades to come. “As a result, it is obviously very important to us that a new owner is able to continue to invest in ITP Aero’s technology, innovation and workforce,” the spokesman said. Last month, Rolls-Royce’s disposal plan suffered a setback when Norway halted the sale of its maritime engine maker to a Russian company on national security grounds. Asked about ITP Aero, the Spanish industry ministry did not immediately respond. Shares in Rolls-Royce traded down 1.7% at 101 pence at 1356 GMT. A source close to the matter said that Rolls-Royce was well aware that any deal for ITP would need to include assurances from the buyer. Bloomberg said Spain was concerned Rolls-Royce could sell ITP to a private equity fund, naming KKR, Bain Capital and TowerBrook Capital as being in the running, and the financial buyers would not have an industrial plan for the unit. ($1 = 0.8292 euros)