TAX uncertainties notwithstanding, Rigel Energy Corporation has spent $30m (#18m) drilling seven wells in the North Sea this year.

But Rigel, the Canadian exploration group with strong North Sea interests and ambitions, said yesterday it was watching the taxation issue carefully.

Rigel took a 20% stake in the MacCulloch field east of Wick last October, buying it from Conoco for #58m.

Earlier last year it bought a 20% stake in the Blake gas discovery in the Moray Firth, which is still being appraised by Rigel and its partners BG and Amerada Hess. The company said then that the ease of buying minority stakes in significant North Sea discoveries was one main factor attracting it to the UK, while the other was the liberal tax regime.

On the uncertainties of the Government's planned changes to the regime, Rick Mitchell, head of investor relations, said at the firm's Calgary base yesterday: ''We will need to see what the taxation issues are, whether it is royalty or tax would be important to us given the stage of life we are at in the North Sea.''

Mitchell said the #18m investment had largely been already spent this year in appraising the Blake discovery.

''BG is operating this project, we are 20% and they are a whole lot bigger than we are.''

He added: ''We are enthused about being in the North Sea and we are just hoping that the fiscal changes will be acceptable.''

The firm's annual meeting in Calgary heard chief executive Don West say Rigel was ''95% confident that this (Blake) is a commercial field and will be developed''.

n THE takeover of Pentex Energy by its offshoot Sibir Energy has been sealed, in spite of the resistance of shareholders who had claimed that the offer undervalued Pentex.

Sibir Energy has now received acceptances for its offer in respect of 94.6% of Pentex's share capital.

The offer of 67 Sibir shares for every 100 Pentex was worth #67m when the bid was launched, but slumped in value as Sibir's share price dropped heavily during the offer period.