By David Stanway and John Ruwitch

SHANGHAI (Reuters) - In the face of a "worrying" rise in protectionism, trade ministers from the world's major economies have agreed to cut trade costs, increase policy coordination and enhance financing, China's Commerce Minister Gao Hucheng said on Sunday.

The Group of 20 trade ministers, who wrapped up a two-day meeting in Shanghai on Sunday, approved a broad trade growth strategy aimed at reversing a slowing in global trade, and backed guiding principles for global investment policymaking.

"The global recovery continues, but it remains uneven and falls short of our ambition for strong, sustainable and balanced growth. Downside risks and vulnerabilities persist," the ministers said in a joint statement.

"We agree that we need to do more to achieve our common objectives for global growth, stability and prosperity."

The specter of protectionism has loomed large over global trade amid sluggish economic growth and is a pressing concern for China.

The country's huge but struggling steel sector has relied on exports to offset the impact of slowing domestic demand, but it has been accused of using unfair pricing to push foreign competitors out of business.

The ministers discussed the need to address overcapacity, particularly in the steel sector, but some disagreed about the need for specific new commitments to resolve the problem, said one senior trade official involved in the talks, declining to be identified because details of the discussions had not been made public.

The joint statement reflected China's concerns that the country was being singled out for blame for a glut that has led to a collapse in global prices, noting instead that excess capacity in steel and other industries is "a global issue which requires collective responses", and that subsidies and government support could cause distortions.

The United States has been a vocal critic of China's excess capacity, saying its pledges have not gone far enough to resolve the problem.

U.S. Trade Representative Michael Froman said in a statement that the G20 had "added to the chorus of voices calling for tackling the root causes of excess capacity for the benefit of both developing and developed countries".

Chinese trade officials have repeatedly stressed that the country has been the victim of overzealous anti-dumping actions by foreign countries, which fail to take into account Chinese efficiency or its low labor and production costs.

The trade growth strategy adopted by the ministers spelled out broad principles for stimulating trade, including lowering costs, boosting trade finance and stimulating the service sector.

The investment policymaking guiding principles urged governments to avoid protectionism in relation to cross-border investment and establish "non-discriminatory, transparent and predictable" conditions for investment.

Global foreign exchange rates, in flux since Britain's referendum to leave the European Union, were not mentioned in the joint statement, and the senior trade official involved in the talks said the issue had not been discussed.

On Britain's exit vote, UK and EU representatives in Shanghai were at pains to stress that they would come up with a "sensible and mature new arrangement", South Africa's Minister for Trade and Industry Rob Davies told Reuters on Saturday.

(Editing by Ryan Woo)