* Allows free float on the OTC market
* Mandatory fx sales and cash deals remain regulated
* To unify rates after finding equilibrium (Adds details)
MINSK, April 19 (Reuters) - Belarus opened the door to a devaluation of its rouble
"The government and the central bank ... will ensure the removal of restrictions on the rouble exchange rate in dealings between banks and companies," they said in a joint statement.
Belarussian banks have so far been allowed to quote the rouble up to 10 percent off the official rate on the over-the-counter market as Belarus sought to avoid a full-scale devaluation.
Having lost a quarter of its foreign currency reserves this year, Belarus has effectively maintained multiple exchange rates since March 30 in a bid to avoid official devaluation as Minsk sought financial aid from Russia.
Analysts have said the rouble's value would fall by about 20-30 percent if allowed to float freely and some form of move had been signalled by President Alexander Lukashenko at the weekend.
Belarussian exporters will still have to sell 30 percent of their foreign currency revenues at the official rate, which was 3,060 roubles per dollar on Tuesday. This rate also applies to cash transactions at retail exchange points.
"Once the equilibrium exchange rate is achieved in trading between banks and companies, further measures (will be taken)... to gradually unify the exchange rate across all market segments," the authorities said. (Reporting by Andrei Makhovsky; Writing by Olzhas Auyezov; editing by Patrick Graham)