Morgan Stanley, which has already written off almost all of its $1.2 billion investment in Atlantic City’s Revel Hotel & Casino, is being asked to invest more.

The Wall Street brokerage, which recently failed to raise the $1.3 billion needed to complete the 53-story project, is being asked by potential investors in the project to pump in an additional $175 million before they would consider ponying up any cash, according to a Standard & Poor’s Leveraged Commentary & Data report yesterday.

Morgan Stanley has yet to come on board with the financing plan, S&P said.

The Post reported earlier this month that Morgan Stanley, using JPMorgan as its adviser, had failed to raise the much needed $1.3 billion needed to complete the long-stalled project.

Mostly, they were soliciting hedge funds.

More sobering Atlantic City news cannot be helping. Revenue fell 9 percent in the first 11 months of the year as growing competition in Pennsylvania and Delaware hurt traffic.

Morgan Stanley did not return calls.