BMW will begin sales of the 2-series convertible in February, the automaker said in a statement.
The rear-wheel-drive model, which has a folding softtop roof, replaces the smaller 1-series convertible. It is a sister model to the 2-series coupe that is already on sale.
BMW has renamed its two-door cars with even numbers.
Since the 1-series convertible went on sale in 2008, BMW has sold more than 130,000 worldwide, the company said.
The 2-series convertible is 72mm (2.8 inches) longer than the outgoing vehicle at 4432mm (174.5 inches) and is now 1774mm wide, 26mm more than its predecessor.
The 2-series convertible's back seats are now easier to enter and BMW has given the new convertible 335 liters of luggage space with the roof up, 30 liters more than before. With the roof down, this shrinks to 280 liters, 20 liters more than the outgoing 1 series, BMW said.
The 2-series convertible will debut at the Paris auto show in October.