Base said the new cost represented a 14% increase over the original $256 million price.

While much of the increase was attributed to design improvements and scope changes, Base said a significant portion of the increase was related to labour costs for construction.

"This is as a result of the direct experience gained in the implementation of project to date, particularly in relation to the manning levels and supervisory input required to achieve schedule," Base said.

"This component of the cost increase is regarded as an investment in implementation risk management."

As well as an equity raising, Base is also considering extending or acquiring additional debt facilities or the reallocation of internal funding in a bid to obtain alternative sources of funding to accommodate for the project's new cost.

Meanwhile, the company provided an update of its $170 million debt finance facility it secured for the Kwale project.

Base said it expects to make the first drawdown of the facility in the December quarter of this year after it satisfied a number of key conditions.

Base has executed off-take arrangements covering 70% of projected revenue and has also executed security documentation, including the government of Kenya's consent to the security interests and the completion of a direct arrangement.

A number of minor conditions remain the subject of a waiver request, which is expected to be confirmed next week.

Base said it could now inject its required equity contribution into Base Titanium, the Kenyan subsidiary developing the Kwale project.

The Kwale project is expected to produce about 4.7 million tonnes of production over 13 years from late 2013.

The company said the project remained on schedule for completion in the September quarter of 2013.

Shares in Base were last trading down 11.8%, or A6c, to 45c.