Charles Green has warned Rangers supporters that any instances of sectarian singing will result in a lifetime ban.

The chief executive reiterated his hardline stance yesterday, after the club revealed its interim results for the seven months to the end of last year, with Rangers having suffered a trading loss of £7m against revenue of £9.5m.

The club was able to post a profit of £9.5m, however, after taking into account non-recurring items, including a "negative goodwill write off" of £20.5m. The share price was unchanged at close of business yesterday.

The profit and loss figures essentially reveal that excepting the non-recurring costs – such as legal fees and old football debts – Rangers are running at a loss due to operating expenses of £16.6m. Costs continue to be reduced, and the period in question also involves two months when Rangers generated no income due to uncertainty about the team's involvement in the Scottish game last summer.

As he discussed the figures, Green addressed the outburst of sectarian singing that was heard during the recent visit to Berwick Rangers, which prompted ESPN, who were broadcasting the game live, to apologise to viewers.

"Sectarian singing, or any form of race or religious discrimination, is not acceptable," said Green. "I know Rangers have made great strides, but anybody who is identified will be banned for life. There will be no appeals and nobody will be let off. If you're stood next to the man and if you are not seen to be policing that, ie putting your hand up and saying, 'arrest my best mate, because of his sectarian chanting', I'm going to ban you as well. I feel so strongly about it.

"I made a pledge to the Rangers fans that I wouldn't leave until we're playing the Champions League music. If we carry on playing this other type of music, we'll get banned for life by UEFA, so I can leave on Friday. That's not what we want. When I get comments like, 'other people do it', I don't care about other people. We've had a fantastic year, we've made lots of friends and for it to be spoiled by a mindless few is ridiculous. This is something that we can stamp out."

Green was bullish about the financial results, pointing out that the costs include high wages that were still being paid to players in the summer, before they departed.