By Lindsay Dunsmuir and Howard Schneider

WASHINGTON (Reuters) - U.S. companies have been battered by the fallout from the novel coronavirus outbreak, with economic activity plunging at an unprecedented speed over the past few weeks, a Federal Reserve report released on Wednesday showed.

The sharp deterioration in the U.S. central bank's latest temperature check of businesses across its 12 districts illustrated the abrupt ferocity of the disruption caused by the pandemic, which has likely seen the economy decline in the first quarter at its quickest pace in decades.

Economic activity "contracted sharply and abruptly across all regions," the Fed said, dispensing with its usual understated caution when describing changes in conditions. Instead, the pages of the "Beige Book" report were peppered with starkly bleak language as many firms reported layoffs and stunted output. (For a graphic, see: https://tmsnrt.rs/3bcfRFh)

The Fed's survey was completed mostly in March but included some of the first week of April. During that time, the United States went from worrying about the risks posed by the virus to most of the country being under some form of stay-at-home order and millions losing their jobs at breakneck speed.

"The hardest-hit industries - because of social distancing measures and mandated closures - were leisure and hospitality, and retail aside from essential goods," the Fed said in the report in which the virus or COVID-19, the respiratory disease caused by the coronavirus, were mentioned 93 times.

"All districts reported highly uncertain outlooks among business contacts, with most expecting conditions to worsen in the next several months," the Fed said.

The central bank has taken unprecedented action since early March to try and keep credit flowing to businesses and households by shoring up liquidity in financial markets. It has launched numerous crisis-fighting programs, slashed interest rates to near zero and is resuming large-scale asset purchases.

Last week it announced a "Main Street" program that would make up to $600 billion in loans available to mostly mid-sized companies, though Fed Vice Chair Randal Quarles said on Friday it would be another two to three weeks until it was up and running.

The U.S. government also has a $349 billion forgivable loan program for small businesses, but it has been hampered by a slow disbursement of funds since it was launched almost two weeks ago. Data released on Tuesday showed that the construction, professional services and manufacturing sectors so far are among those topping the list of recipients.