Complex sentence: Since the Sprint-Nextel Merger in late 2005, Nextel Central has been rebranded as Sprint Central, however in late February 2008, the Sprint Nextel Corporation terminated their sponsorship contract.
Split into simpler sentences: Since the Sprint-Nextel Merger in late 2005, Nextel Central has been rebranded as Sprint Central. However, in late February 2008, the Sprint Nextel Corporation terminated their sponsorship contract.