* Three ships, submersibles being used in recovery

* Shipwreck was most deadly in Mediterranean in decades

* About 4,400 migrants rescued in 2 days - coastguard

By Steve Scherer

ROME, June 29 (Reuters) - Italy's navy said on Monday it had begun to recover the bodies of up to 800 migrants from a fishing boat that sank in the Mediterranean three months ago, a tragedy that prompted the European Union to expand sea rescue operations.

The 20-metre fishing boat capsized and sank in April as it approached a merchant ship that had come to its aid. The shipwreck, the most deadly in the Mediterranean in decades, became a symbol of Europe's long-running migration crisis.

Three navy ships and remote-controlled submersibles have been used to take bodies from the sea bed near the shipwreck, which is about 135 km (85 miles) north of Libya at a depth of about 370 metres (1,214 ft), the navy said in a statement.

No further details about the operation were provided.

Prime Minister Matteo Renzi has said he wants the vessel lifted so "the whole world (can) see what happened".

Italy has accused EU governments of not pitching in enough to help manage the migrant flow, mainly from conflict zones in Africa and the Middle East.

Efforts to establish mandatory quotas for a small portion of asylum seekers throughout the European Union were rejected last week in favour of a voluntary system.

About 60,000 migrants have arrived in Italy by boat from North Africa this year, after 170,000 last year, and almost 2,000 have died, according to official estimates.

On Sunday and Monday, Italy's coastguard organised the rescue of 4,400 migrants from 29 boats. British, Irish, Italian, Swedish and Spanish ships took part in the rescues, a coastguard spokesman said.

The Phoenix, a privately funded ship based in Malta, and vessels taking part in the EU-funded Triton border control operation, which was tripled in size after April's shipwreck, have also helped with rescues, the spokesman said.

The turmoil in Libya, which has become one of the main transit routes to Europe, is giving free rein to people smugglers.

EU ministers last week approved a naval operation to try to fight smuggling and halt the stream of migrants, though it will be limited for the moment to intelligence gathering because it has no authorisation from the United Nations.

(Reporting by Steve Scherer; Editing by Janet Lawrence)