* April export data suggests Iran's output rising

* Iran ready to help support market when at pre-sanctions output

* Opec meets next on June 2 

Talks between Opec and non-Opec producers to freeze production broke down on Sunday when Saudi Arabia insisted that all members of the exporter group, including Iran, and non-Opec producers should join in the deal.

Iran is concerned by oversupply and low oil prices but is ramping up its own production and reclaiming market share after the lifting of Western sanctions in January and has said it would not change its stance until output reaches pre-sanctions levels.

State news agency Irna quoted deputy minister Rokneddin Javadi as saying the pre-sanctions level would be attained by the end of the Iranian month of Khordad, which falls on June 20.

That and comments from Iranian oil sources indicate that the next meeting of the Organisation of the Petroleum Exporting Countries in Vienna on June 2 could see Iran willing to join any renewed effort for supply restraint.

"Iran would support any move towards market restoration and stability of the market as well as cooperate with Opec and non-Opec," a source familiar with Iranian oil policy told Reuters after Sunday's Doha meeting failed to reach a deal.

"Iran will join any effort to that end soon after reaching pre-sanctions production."

The country has boosted its crude exports to about 1.75mn barrels per day (bpd) so far in April, according to an industry source and shipping data, up from average March exports of about 1.6mn bpd.

That is a slower rise than Iran says is taking place. Last week Javadi said that output had already surpassed 3.5mn bpd and exports would reach 2mn bpd in the coming month.

Iran exported about 2.2mn bpd and its production was below 4mn bpd in late 2011 before the sanctions over Tehran's nuclear programme were tightened.