Yes, what you say is right. In fact, NTL is worth more than TEO per share, but in the last few years the best that ever happened is NTL reached about the same price as TEO. Based on TEO price today (about 10.7) NTL is worth over 13.50. One reason it trades lower is because of lack of liquidity. There are more than 3 times the number of TEO shares as NTL shares available to trade (at least, since I don't know who owns all the NTL shares). The last few days have seen much bigger than usual volume.

Once the dividends start the market will wake up. This might take a couple of years though.