Complex sentence: In 1993, he was invited to meet with two groups interested in reforming the South African Broadcasting Corporation (SABC), which, until then, had been the mouthpiece of the Apartheid government.
Split into simpler sentences: In 1993, he was invited to meet with two groups. The first was interested in reforming the South African Broadcasting Corporation (SABC), which, until then, had been the mouthpiece of the Apartheid government.