asked the Minister for Energy what was the British share of ownership in the consortium which received licences for North Sea oil exploration in each of the four separate rounds of distribution of licences; what is the British share in the consortia who are licence holders for the fields already established; and what is his latest estimate of the British share of total North Sea oil production.

The following table sets out on a round-by-round basis the percentage share of territory licensed to British interests—taking Shell as 40 per cent. British—when the licences were first issued.

	British interest per cent.
First round	26·2
Second round	28·3
Third round	36·4
Fourth round (i) Auction	20·0
(ii) Discretionary .	34·8
(iii) Total	34·0

Because of uncertainties about the exact size of the fields so far considered to be commercial it is not possible to give a firm figure for the British share. It is estimated however that the share of recoverable reserves held by British interests in these fields is some 40 per cent.—50 per cent., or about 300–400 million tons. If further appraisal drilling confirms that other finds already reported are commercial the latter figures could be higher.