Shares in construction and maintenance firm Transfield Services plunged almost 12 per cent as analysts anticipate a writedown on its newly acquired Easternwell business.

The company’s shares lost 29 cents to a near two-month low of $2.20 on Wednesday, after a trading halt requested to announce a profit downgrade was lifted.

The downgrade was caused in part by an earnings downgrade for Easternwell, a resources sector services company, the second in two months.

That has raised the prospect of a writedown in the value of the business, Commonwealth Bank analysts said.

Transfield bought Easternwell in late 2010 for $598 million in the hope it would be a strong contributor to earnings.

In February, Transfield lowered its 2011/12 earnings forecast for Easternwell to $87 million from $100 million.

Easternwell’s earnings have since been hit by $7.4 million of unforeseen costs relating to a recent cyclone in Western Australia and wet weather in Queensland.

“We believe this event may increase the chance of an Easternwell impairment at the full year 2012 result,” Commonwealth Bank analysts Ben Brownette and Sam Teeger said in a research note.

“It makes little sense to us that earnings can continue to be deferred without impacting the recoverable amount used by auditors in impairment testing.”

The latest earnings downgrade for Easternwell, plus $1.6 million in costs to other Transfield operations due to extreme weather and a $16 million provision on a construction contract in New Zealand, forced Transfield to cut its full year profit forecast by about one fifth.

It has forecast a profit of $105 million for the year to June 30, down from its previous forecast of $130 million to $135 million.