UPDATE 1-Bidder Melrose opposed to rapid break-up of GKN

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LONDON, Feb 1 (Reuters) - Melrose Industries said it would not pursue a "hasty separation" of GKN's automotive and aerospace divisions as it set out its 7.2 billion pound ($10.2 billion) hostile bid for the British engineer on Thursday.

GKN, which has rejected turnaround specialist Melrose's unsolicited approach, wants to pursue its own plan of separating itself into its automotive parts and aerospace divisions.

In a letter to shareholders on Thursday, Melrose Chairman Christopher Miller said while the two needed investment, splitting them up was not the best course of action.

"Any actions to immediately separate the businesses in preparation for a sale would be value destructive," he said.

The Financial Times reported last week that GKN had received several approaches for its individual businesses.

GKN, whose roots date back to the 18th century, makes parts for the Boeing 737 jet, Black Hawk helicopter and components for Volkswagen and Ford cars.

Melrose is attempting to snap up GKN after the engineer was left weakened by profit warnings in October and November, double blows that were both sparked by problems at its aerospace division and sent its shares sharply lower.

GKN's vulnerability was exacerbated by its lack of a permanent chief executive until former Ford executive Anne Stevens was appointed last month.

The document said Melrose's offer, consisting of 1.49 new Melrose shares and 81 pence per GKN share, represented a total value of 418.3 pence per GKN share.

GKN's shares closed at 422.8 pence on Wednesday, while Melrose closed at 226.4 pence. GKN shares gained 1 percent to 427.4 pence by 0820 GMT on Thursday while Melrose was up 1.3 percent at 228.9 pence.

Melrose said GKN shares had risen from 326.3 pence since it first approached the company, telling investors it had added 1.7 billion pounds in value.

Melrose had made a firm paper-and-cash offer valuing GKN at 430.1 pence per share in January, worth 7.4 billion pounds at that point.

If accepted, Melrose said the acquisition would create an industrial powerhouse worth over 10 billion pounds.

Thursday was the first day on which Melrose could detail its formal bid under British takeover rules.

FTSE 100 engineering company GKN now has 14 days to publish its defense against the bid. ($1 = 0.7034 pounds) (Reporting by Emma Rumney; editing by Adrian Croft and Keith Weir)