Complex sentence: Glaxo Wellcome and SmithKline Beecham announced their intention to merge in January 2000; the merger was completed in December that year, forming GlaxoSmithKline (GSK).
Split into simpler sentences: Glaxo Wellcome and SmithKline Beecham announced their intention to merge in January 2000. The merger was completed in December that year, forming GlaxoSmithKline (GSK).