BMW E46 year 2000 automatic?

Hi!

New to this site and have a question to put out there.
I'll try to explain my problem as fully as possible.

OK... I have a 318i SE E46 (year 2000) and have had an issue with starting. When I turn the key the starter engages and catches almost straight away only for the engine to peter out and die. This happens about 3 times before the engine fires up. This is however intermittent; sometimes it catches straight away with no problem, other times it has taken up to 7 goes before it starts. 
Anyone out there who could be of any help with ideas on any remedies