British Airways chief executive Willie Walsh has vowed the airline will not surrender runway slots at Heathrow in order to land its proposed alliance with American Airlines, the Sunday Times reported.

Walsh told the paper that BA would not give up any of the prized slots, which have changed hands for GBP20 million pounds (USD$37.45 million) a pair, just as competition regulators are tipped to demand that the two carriers forego up to 10 slot pairs a day.

"There should be no slot remedy, I don't see how it could be justified." he said.

Both airlines along with Spain's Iberia said on Thursday they had agreed to a transatlantic tie-up and would file for antitrust immunity from the US Transportation Department and notify EU regulators.

BA, which is also in all-share merger talks with Iberia, holds over 40 percent of Heathrow's slots.