Lufthansa increasing its 30 percent stake in British airline BMI is "an option," Wolfgang Mayrhuber, CEO of the German carrier, said in an interview pre-published on August 25.

"We have decided to keep quiet on the details, but BMI is an option," Mayrhuber said in an interview with German business weekly Wirtschaftswoche to be published on August 27.

Press reports have for months said that Lufthansa was very interested in buying the 20-percent stake in BMI currently held by Scandinavian Airlines System (SAS).

SAS said in June that it would focus on its core business and sell off a number of assets, including its stake in BMI.

BMI is relatively small but is interesting for major carriers because it holds 12 percent of the take-off and landing slots at London's Heathrow airport, Europe's busiest.

Takeover rumours regularly do the rounds and British Airways was most recently said to be preparing to buy BMI. The former is not listed and is majority owned by its founder and chief, Michael Bishop, who holds 50 percent plus one share.