British Airways stated its passenger load factor - the amount of capacity taken up - fell 2.1 percentage points in April, but that the airline boosted its capacity by 0.5 percent in the same month.
Passenger load factor slipped to 76.9 percent in April, the company said in a statement. Overall load factor - which includes cargo - fell 0.7 percentage points to 70.9 percent.
"Underlying market conditions are broadly unchanged," British Airways said.
British Airways said last month it has contacted private equity investors about joining in a possible bid for Spanish airline Iberia SA.
Iberia announced in March that it had been approached about a possible takeover offer worth more than 3.4 billion EUR(US$4.6 billion) from U.S. private equity firm TPG Capital LLP, formerly known as the Texas Pacific Group.
British Airways shares fell 1.7 percent to 510 pence (US$10.17; 7.48 EUR) on the London Stock Exchange.