According to Windpower Intelligence, the two companies, which were both ranked in first and second places in terms of installations in 2012, were far ahead of the remaining manufacturers.
However, most of GE's contracts were confined to the US. This was in contrast with Vestas, whose orders included Romania, Italy and Ukraine.
South American manufacturer Impsa was in third place with 180MW of orders, followed by Nordex and Gamesa on 161MW and 154MW respectively.
Elsewhere, the UK installed the greatest capacity over the April period by adding 699MW. In second place was Italy on 182MW. The US was back in sixth place, on 112MW, behind China and Australia.
"The two giants are locked in stiff competition," said Eric Prideaux, editor of Windpower Intelligence and Data, the market research unit of Windpower Monthly.
"GE's lead in April is attributable to a small number of large projects in the uncertain US market," said Prideaux. "Though Vestas' total orders were smaller, that firm stands to benefit from strategic footholds in several emerging markets."
In April, Windpower Intelligence tracked Vestas orders totalling 108MW in Chile, signalling a keen focus on the buzzing Latin American market.