* Greek lawmakers to vote on reform law on Sunday
* Vote will allow euro zone officials to release 2.8 bln of aid on Monday
* Euro zone finance ministers to release 6 bln eur more on May 13
ATHENS, April 27 Senior euro zone officials will meet on Monday to approve payment of another 2.8 billion euros ($3.65 billion) in rescue loans for Greece, on condition that the country's lawmakers approve a reform law the day before, the country's finance minister said on Saturday.
Monday's meeting will be held by the Eurogroup Working Group, which mainly consists of euro zone deputy finance ministers or senior treasury officials, Greek finance minister Yannis Stournaras told lawmakers on Saturday.
Pending further measures by Athens, euro zone finance ministers will then meet on May 13 to release a further 6 billion euros of rescue loans, he added.
Greece needs that money to pay wages, pensions and bonds held by the European Central Bank that mature on May 20, Stournaras said, urging lawmakers to approve the reform law they started debating on Saturday.
"Passing the bill opens the way for the disbursement of the 2.8 billion euros ... it doesn't get more urgent than that," he said, explaining why the government submitted the law under a fast-track, two-day procedure.
The law contains several reforms and tax measures Athens agreed with its international creditors earlier this month, including provisions that facilitate the dismissal of public sector workers.
Lawmakers will debate and vote on the draft law in a full session of parliament late on Sunday. It is expected to pass easily, with the backing of the three parties forming Greece's ruling coalition.
Athens has already obtained about 200 billion euros of EU/IMF rescue loans since mid-2010 and is set to get about 40 billion euros more by the end of 2014.