Almost $490 million has been wiped from the market value of finance group McMillan Shakespeare as changes to fringe benefit tax (FBT) laws are set to severely damage its business.

After emerging on Thursday from a week-long trading suspension, the company’s shares lost close to half their value in morning trade.

The price recovered a little during the day and closed at $8.80, down $6.56 or 43 per cent.

McMillan Shakespeare’s market value now stands at $656 million, down from $1.14 billion nine days ago.

The company has criticised the federal government’s decision last week to tighten FBT guidelines on car leasing and salary-sacrifice packaging.

“The proposed changes … is creating disruption within the industry and is expected to lead to an unknown and unquantifiable decrease in demand for novated leases and an adverse impact to the business overall,” it said in a statement.

McMillan Shakespeare provides salary packaging and vehicle leasing administration.

While the government’s proposals are yet to pass parliament, McMillan said the changes would have a “material adverse impact” on the company’s future earnings.

Chief financial officer Mark Blackburn said McMillan would suspend all communication with investment analysts, shareholders and the media until after the election “unless the position becomes clearer prior to then”.

McMillan expects to have made a net profit of between $61 million and $63 million in the 2012/13 financial year, about a 15 per cent increase on the prior financial year.