Complex sentence: The fourth serial, originally conceived of as a Republic TV series, was first released (for contractual reasons) as a theatrical serial; two years later, it was finally syndicated on TV as twelve 25-minute episodes.
Split into simpler sentences: The fourth serial, originally conceived of as a Republic TV series, was first released (for contractual reasons) as a theatrical serial. Two years later, it was finally syndicated on TV as twelve 25-minute episodes.