Software firm Misys called off talks over a possible bid for the firm and said its chief executive, who was involved in a potential offer, would step down, sending its shares more than 20 percent lower.

Misys said on Monday that after about four months of bid interest it had not received a firm offer.

Accordingly, the independent committee (of Misys) has... terminated the offer process with immediate effect, it said in a statement.

The healthcare and banking software firm said Chief Executive and founding investor Kevin Lomax, who was involved with one potential bid, was stepping down immediately.

The absence of a bid for the company greatly diminishes the likelihood of a value enhancing event and should put the stock under tremendous pressure, Collins Stewart analysts wrote in a research note, pointing out that Misys shares were trading at around 190 pence before news of the bid interest.

At 9:32 a.m., the shares were down 17.8 percent at 186 pence, off a low of 178p, valuing the business at about 1 billion pounds.

Misys also said in a trading update it expected adjusted earnings per share for its current financial year to be below the previous year, due to the sale of its general insurance business, exchange rate moves and a rise in U.S. interest rates.

Bridgewell Securities analysts said they were forecasting annual earnings per shares of 14.1 pence, down from 14.2 pence the year before.