Beckworth was due to pay almost dollars 1.6m under an underwriting agreement made when Quadrant, whose core business is photographic imaging, bought two ships from it last year. Beckworth agreed to underwrite the whole of the charter earnings from the liquid petroleum gas tankers for three years.
Quadrant drew dollars 1.5m from an escrow account set up at the time of the sale to settle the shortfall for the first two quarters of the deal to 29 February.
The escrow account is now exhausted and when the shortfall of dollars 1.6m for the quarter to the end of May fell due this week, Beckworth failed to pay.
Mr Brothers resigned as chairman of Quadrant after a late- night board meeting that went on until the early hours of yesterday morning. The company's shares plunged 9p to a new low of 20p on the news.
The new non-executive chairman is Lord Rees, chairman of Lasmo.
Quadrant bought the ships in May 1991, largely to reduce the capital gains tax liability arising from the sale of its cellular telephone installation and distribution business for pounds 19m in 1989.
The company paid Beckworth pounds 9.9m for them, as part of a deal in which Mr Brothers bought 16 per cent of Quadrant from the previous chairman, Jeremy Peace, for pounds 6.5m, and became chairman.
The chief executive, Andrew Douglas, confirmed that Mr Brothers is still a director and retains his stake in the company, which now stands at 18.5 per cent.
Mr Douglas said the board was determined to pursue shareholders' interests, and would be having urgent negotiations with Mr Brothers. The issue of whether Mr Brothers should remain a director was also to be resolved.
The company said the board had reason to believe that Beckworth might not meet its future commitments under the underwriting agreement.
Quadrant reported pre-tax profits of pounds 1.4m for the year to 29 February, a fall of almost 50 per cent on the previous year.Reuse content