Tighter bank financing is the big threat to shipping companies, and many are looking at alternative sources of funding such as private equity to fill gaps amid a worsening credit squeeze, a transport survey showed on Friday.

In the survey by international law firm Norton Rose, 42 percent of respondents said a lack of finance was the greatest threat to their businesses.

Many banks are keen to shed dollar-denominated assets such as ship and trade finance loans to meet tougher capital rules imposed on euro zone lenders.

The past three years has seen a notable decline in the availability of bank lending to the shipping sector, and this has had a considerable impact on many shipping businesses, Norton Rose global head of transport Harry Theochari said.

UniCredit , Italy's largest bank by assets, is scaling down its ship financing operations to boost its capital reserves. Industry sources told Reuters that Lloyds Banking Group aimed to sell its $10 billion portfolio of shipping loans.

Almost a third of respondents in the survey, 31 percent, expected their primary source of funding over the next two years to come from private equity, and 18 percent said it would come from export credit agencies. Nevertheless, 43 percent still expected their primary source of funding to come from bank debt over the next two years.

Shipping companies are now looking beyond traditional forms of finance and are readying their businesses to weather further economic uncertainty over the next 12 months, Theochari said.

Shipping companies, especially in the oil tanker and dry bulk sectors, have been hit by weak earnings and an oversupply of vessels ordered in the good times.

The survey found 55 percent believed their key priority was to maintain cash reserves and secure funding lines, with 56 percent planning joint ventures or mergers over the coming year.

Shipping is facing challenges on a number of fronts, from a reduction in the amount of debt available to an oversupply of vessels within some areas of the market, Simon Hartley, Norton Rose head of shipping, said.

Despite this, the sector is proactively putting plans in place to adapt to market conditions, and a significant number are seeking opportunities in new markets and planning joint ventures and mergers.

France's two biggest listed banks, Societe Generale and BNP Paribas , also plan to exit or shrink non-core businesses such as shipping, according to bank memos.

In the Norton Rose survey, which also covered aviation, 59 percent of respondents from that sector said they would pursue a joint venture or merger in the next 12 months.

Almost two thirds said economic uncertainty remained the greatest threat to the stability of aviation companies.

Consolidation in the airline industry continues, indicating that there is scope for growth despite expectations that 2012 will be another difficult year for the transport industry, Norton Rose partner Duncan Batchelor said.

The Norton Rose survey canvassed views from 1,100 international participants from a range of companies involved in transport including financiers, ship owners and operators, manufacturers and government entities, including 515 from the aviation sector and 263 from the shipping industry.

(Reporting by Jonathan Saul, editing by Jane Baird)