The merger of British Airways and Iberia, the Spanish flag carrier, may be delayed until the summer as the two sides continue to haggle over the terms of the deal.

The negotiations are progressing slowly, sources in Madrid say, and they do not expect all the outstanding problems to be resolved for several more months.

Willie Walsh, the chief executive of British Airways, appeared to confirm the slow progress yesterday when he told a Spanish newspaper that he was under no time pressure to complete the deal. “These negotiations aren’t a distraction for our management team,” Mr Walsh said. “BA and Iberia know each other very well, so I don’t feel under any calendar pressure.”

Mr Walsh’s comments have been interpreted as an indication that a deal will not be completed soon.

The Times revealed last week that there had been little progress on the BA-Iberia deal since the start of this year and that no deal was imminent.

Insiders now believe that it will take until at least the summer to complete the deal, which could mean a year after the talks were announced last August.

The slow progress is at odds with statements made by both BA and Iberia in recent months, which appeared to indicate that a deal was close.

Fernando Conte, the chief executive of Iberia, said that March would be decisive for the merger and his comments fuelled speculation that a deal could be ratified at the Iberia board meeting at the end of the month. The meeting came and went with no decision.

In London, Mr Walsh told share holders at BA’s investor day in early March that the only remaining issue to be resolved was how the parent company would be controlled, which again led to speculation that a deal was close.

However, sources close to the deal have said that there are at least a dozen outstanding matters to be settled, including control of the parent company.

BA and Iberia plan to keep their brands and operations separate with the parent company managing both.

Other sticking points include BA’s £2.1 billion pension fund deficit and the shareholding that each set of investors will get in the merged entity.

Mr Walsh reiterated his position on the relative shareholdings yesterday, saying that he would accept nothing less than 53 per cent of the combined group being held by BA’s shareholders. He added that he had no problem with Caja Bank, which owns 23 per cent of Iberia, being the combined group’s largest shareholder. “I would be delighted to have a financial institution with cash as our leading shareholder, given the market crisis,” Mr Walsh said.

The BA chief also said that Madrid Airport would be key to the growth of the company after any merger. Analysts said that this might be an attempt by BA to curry favour with the Spanish Government, which owns both the airport and Caja Bank.

However, BA’s base at Heathrow is full and expansion is unlikely for several more years so the carrier may also be looking at increasing capacity through Madrid.

Meanwhile, BA continues its talks with trade unions over a two-year pay freeze and changes to working practices. The airline has given its 13,500 cabin crew a list of 32 possible changes, which include reduced holiday and fewer or no bonuses for longhaul travel.

Unite, which represents the cabin crew, has said that it is willing to discuss temporary solutions to help the airline through a difficult year but has ruled out permanent changes to employee terms and conditions.

Times Recommends

• Lies and cover-up at MG Rover exposed by report
• High oil prices push manufacturing costs up
• Primark founder steps down as chief executive