Details were being kept under wraps last night, but the Belfast Telegraph understands a special company is to be established working both in the US and in the province.

Private sources last night said it could involve between £150m to £200m from pension funds in the United States. First Minister Ian Paisley and Deputy First Minister Martin McGuinness were expected to attend the formal announcement in New York later today.

Stormont sources insisted they could make no comment. But it is thought Mr Paisley and Mr McGuinness hope the announcement will kick-start momentum towards the United States Investment Conference in the province next month.

It is understood Executive Ministers were given details of the package at their meeting yesterday, but warned that going public too early could affect the pension funds involved on the stock exchange.

Then came an invitation from New York City Comptroller William C. Thompson Jnr, in which it was announced he would hold a press conference with the two leaders.

They are to be joined by trustees from New York City Pension Funds announcing "the largest public investment to date in Northern Ireland," the invitation read.

Some sources last night suggested the investment could involve a degree of "asset-stripping" in the province which could prove controversial.

Mr McGuinness, who had been expected back from the United States yesterday to chair the Executive meeting, was instead last night travelling to meet up with Mr Paisley.