Complex sentence: Pierer studied law and economics in Erlangen and joined Siemens in 1969 and from 1977 he worked for the company's power generation subsidiary "Kraftwerk Union AG" (KWU).
Split into simpler sentences: Pierer studied law and economics in Erlangen and joined Siemens in 1969. He joined Siemens in 1969 and from 1977 he worked for the company's power generation subsidiary "Kraftwerk Union AG" (KWU).