Melrose claims its £7.4 billion hostile bid for GKN would create one of the largest firms in the UK, worth a combined £11 billion.
Here are some facts about the companies:
1. GKN employs more than 58,000 employees across more than 30 countries, with about 6,000 staff in the UK.
2. It is headquartered in Redditch, Worcestershire, but also has a corporate office in London and 10 manufacturing sites across the UK, supplying aerospace, automotive and agricultural products.
3. It has four main divisions - GKN Aerospace, GKN Driveline, GKN Powder Metallurgy and GKN Additive.
4. Major UK sites include the Western Approach manufacturing base for GKN Aerospace in Bristol.
5. GKN was founded in 1759, tracing its roots back to a small ironworks in Dowlais, South Wales.
6. Suitor Melrose is a turnaround specialist with a stock market value of £4.5 billion, making it far smaller than GKN.
7. Since listing in 2003, Melrose has made four major acquisitions including engineering group Elster, which it bought for £1.8 billion in 2012 and sold for £3.3 billion to Honeywell three years later.
8. It still owns Brush, acquired as part of the FKI business in 2008, and Nortek, which was bought in August 2016.
9. Brush has manufacturing bases at UK sites including Loughborough, the Americas and Asia Pacific while Nortek has bases across Europe, the US and Asia.