By Ainsley Thomson 
 

LONDON--Prime Minister David Cameron Monday urged the leaders of the U.K.'s offshore financial centers--including Bermuda, the Cayman Islands and Jersey--to "knock down the walls of company secrecy" and take measures to find out who really owns and controls each and every company, as Britain steps up its fight against tax avoidance and evasion.

In a letter to the leaders of 10 U.K. crown dependencies and overseas territories, Mr. Cameron said while he respects their right to be lower tax jurisdictions, low taxes are only sustainable if what is owed is actually paid and if international tax rules are enforced fairly to create a level playing field across the world.

"There is no point in dealing with tax evasion in one country if the problem is simply displaced to another," Mr. Cameron said.

The prime minister called on the crown dependencies and overseas territories--Bermuda, British Virgin Islands, Cayman Islands, Gibraltar, Anguilla, Montserrat, Turks and Caicos Islands, Jersey, Guernsey and the Isle of Man--to establish centralized registries that contain information about who owns and controls companies operating within their jurisdictions.

"These will need to provide for fully resourced and properly managed centralised registries, that are freely available to law enforcement and tax collectors, and contain full and accurate details on the true ownership and control of every company," Mr. Cameron said.

Mr. Cameron's letter comes amid a crack-down by his government--and other governments across Europe--on tax evasion and avoidance in response to the heightened public resentment about the seemingly low taxes paid by some large firms and individuals during a period of austerity.

The U.K.'s crown dependencies and overseas territories present a conundrum for the government: while the low tax regimes and light touch regulation has allowed them to become flourishing financial centers that are not reliant on handouts from the U.K. government, it has left them open to accusations that they are havens for individuals and companies looking to minimise their tax bills.

Last month, Austrian Finance Minister Maria Fekter--under pressure to ease her country's strict banking secrecy laws--pointed her finger at the U.K.'s crown dependencies and overseas territories, labelling them a paradise for money laundering and tax evasion.

The U.K. government has been working hard to bring the crown dependencies and overseas territories into line and has already reached agreement with them to share information about bank accounts. But although the U.K. represents them on the international stage, the territories have legal systems that are independent of the U.K.

On Wednesday, Mr. Cameron will attend a summit of European Union leaders in Brussels where tax evasion and avoidance is on the agenda.

Meanwhile, the prime minister will meet with Google Inc. (GOOG) Chief Executive Eric Schmidt later on Monday, with the issue of the internet giant's U.K. tax affairs expected to be discussed.

The meeting comes after U.K. lawmakers last Thursday accused the company of manipulating how it characterized its business in Britain to lower its tax bill, a claim denied by Google which says it complies fully with tax laws.

Mr. Schmidt on Sunday wrote an article in The Observer newspaper in which he said Google tried to "do the right thing," with regard to its tax affairs, but said that international tax rules were complicated and could benefit from reform.

He added that while profit was sometimes regarded as a "dirty word," it was worth remembering that corporate profits led to job creation and investment in research and development, which ultimately led to higher tax revenue.

Write to Ainsley Thomson at ainsley.thomson@dowjones.com