A special Senate committee investigating price rises in the Australian and global fertiliser market has released a draft report highlighting preliminary evidence which points to monopoly and anti-competitive behaviour in the market.

It said market domination, by Incitec Pivot in particular, was compromising serious competition.

The committee, headed up by Liberal Senator Bill Heffernan, won't release its final report until June next year.

But the draft says the committee noted recent mergers and acquisitions in the industry which it believes have resulted in "an increase in market concentration and a lessening of competition".

"The committee considers that the market dominance of large players in the fertiliser industry seriously compromises effective competition in the industry," the report says.

"This in turn has implications for the pricing of fertiliser products in this country.

"The committee believes that an effective monopoly may exist in relation to the fertiliser industry in Australia – with the market dominance of Incitec Pivot in eastern and southern states and CSBP in Western Australia.

"The committee considers that the fertiliser industry operates in a distorted market not governed by the usual supply and demand factors and is, to a large extent, a law unto itself in the setting of fertiliser prices."

The report cites numerous examples of alleged abuses of market power, including difficulties for smaller companies to access port warehousing facilities for imported fertiliser products.

* More in this week's Rural Press weekly agricultural newspapers.