However a spokeswoman for Collins Stewart declined comment on the Chicago Environmental initial public offering (IPO).

The UK broker's handling of IPOs featured heavily in a series of complaints filed last month by Middleweek to the UK's market regulator, the Financial Services Authority, according to court documents.

Collins Stewart has denied all of Middleweek's allegations.

On August 28 Collins Stewart helped GX Networks plc GXN.L raise 12 million pounds in a share placing, but Chicago Environment will be the first full IPO it has taken part in since Middleweek's allegations surfaced earlier that month.

Collins Stewart's shares closed up 1.7 percent at 382-1/2p, still over 20 percent below the 490p level on August 22 before the dispute was first made public.

Helping smaller companies list on UK markets is a staple of Collins Stewart's business. The bank is currently third in Dealogic's European IPO bookrunner league table, after helping four companies come to market this year. It finished twelfth last year.

According to a statement issued through the London Stock Exchange, Chicago Environmental is looking to place up to 15 million pounds worth of stock and will begin trading on London's junior AIM market on Thursday.

Chicago Environmental will invest the cash it raises through the IPO in the Chicago Climate Exchange (CCX), an exchange where companies are given credits for cutting carbon dioxide omissions. The plan allows companies that cut emissions more than they initially pledged to sell credits to firms unable to meet required reductions.

Companies trading on CCX also can earn credits for emission reductions programs, such as reforestation projects.

The listed fund will also be able to invest in other environmental projects.

The four-year pilot program aims to reduce greenhouse gas emissions by 50 million to 60 million tonnes by 2006, CCX said earlier this year.

The CCX has some big name backers, including Ford Motor Co F.N , Motorola MOT.N and the City of Chicago. A London-based spokesman for Chicago Environmental did not immediately have any further detail on the listing.