EXHIBIT 4.4

PERSONAL

Sir William Castell
Chief Executive
Amersham plc

20 February 2003

Dear Bill

I am pleased to confirm that the Remuneration Committee has approved an
increase in your salary to L660,000 per annum with effect from 1 April 2003.
Additionally, in respect of the 2002 Bonus Scheme, the combination of
performance against financial targets and your personal objectives has produced
a bonus of L397,200.

I am also pleased to confirm your award of share options today with a nominal
value of approximately L1,200,000. The performance conditions will be similar
to those adopted last year.

With best wishes.

Yours sincerely

RICHARD LAPTHORNE
CHAIRMAN