Complex sentence: The Airline Group, a consortium of Airtours, British Airways, bmi, Britannia, easyJet, Virgin Atlantic, and Monarch, holds 42%, with the remaining shares owned by BAA (4%) and NATS employees (5%).
Split into simpler sentences: The Airline Group, a consortium of Airtours, British Airways, bmi, Britannia, easyJet, Virgin Atlantic, and Monarch, holds 42%. The remaining shares are owned by BAA plc (4%) and NATS staff (5%).