London interdealer broker Icap has upped its bid for Plus Markets SX, the UK’s junior stock exchange, by £500,000, agreeing to meet the costs of a hotly-disputed pay deal for the firm’s senior management in the event of a sale.

The bid is a £500,000 increase on the previous nominal sale price of £1, which was agreed based on the loss-making nature of the business. The new offer is designed to meet £423,000 in parachute payments to the firm's executive directors, which Plus Markets is contractually obliged to meet in the event that its stock exchange arm is sold.