British Airways Executive Club members who fly with Finnair from Helsinki to Japan can earn up to double bonus Avios.
The three routes eligible for the offer are from Helsinki to Tokyo Narita, Nagoya and Osaka. Travel must be booked and taken by February 29.
BA, Finnair and Japan Airlines started a joint business venture on flights between Japan and Europe in April last year (see news, March 2014).
Bronze Executive Club members will earn 25 per cent additional bonus Avios, while Silver members will earn 50 per cent and Gold members 100 per cent.
To qualify, members must first register online here before taking their flights. Eligible classes in business are J, C, D and I; in economy, they are Y, B, H, K, M, P.