TV Barrandov and Slagr TV have joined the growing list of Czech channels now offering HbbTV services.
They are working with the national transmission company Ceske Radiokomunikace (CRa), as are FTV Prima and TV Ocko.
According to CRa, the last major milestone in the intensive work it is undertaking in HbbTV is the ability to use time synchronisation with the TV broadcast within an accuracy of a few tenths of a second.
The Czech Republic has played a key role in the introduction of HbbTV services in Central and Eastern Europe, initially through publicly owned Ceske Televize (CT).
Last month its leading broadcaster TV Nova said it has plans to introduce HbbTV ads.